People are confusing being one of the most played cards with being one of the most powerful. Sol Ring is colorless and universally powerful, but it's not by any stretch one of the most powerful cards. Let's leave aside that Mana crypt is stronger, even with the 1.5 damage per turn, because its free, meaning you can use that (possibly colored) Mana from your turn 1 land to cast something (essentially giving you an extra Mana the turn you play it compared to Sol Ring) and it is much more abuseable with ways to bounce it. So if we're talking about banning just one piece of fast Mana, Sol Ring shouldn't be it, Mana crypt should be. More importantly, Sol Ring has a pretty damn narrow window in which it can ruin games. It has to land in the first few turns. We aren't talking about some guy dropping Sol Ring turn 5 so he can cast his 6 drop commander, or dropping it turn 3 to set up that same 6 drop on turn 4, and saying that's problematic. No, we are discussing the narrow range of play where a turn 1 or 2 Sol Ring into signet play sets you significantly ahead on Mana, or some combination of rocks and ramp including sol ring in the first 3 turns gets you to seven Mana. Even the, the player achieving this sort of sequence needs to have a way to translate that early Mana advantage into a win. In cEDH, yeah that's usually going to end up being a win without an opponent holding an immediate answer, but as you go down in competitiveness this becomes less and less certain, because doing this makes you the archenemy and that is a significant downside outside of cEDH. In a 75 percent meta, the deck achieving this is probably going to have a way to press the advantage, but the opponents are more likely to run answers to disrupt it, and all of them should be focused on the clear threat. In a more casual meta, those answers and the coordination are both less prevalent, but so is the ability of the deck hitting ring into signet to press their Mana advantage into a quick victory, and thus their opponents are more able to catch up and stabilize before the Sol Ring signet player can knock them out. And of course, all this is assuming that only one person gets Sol Ring into signet or a bunch of ramp by turn 3 and everyone else is stuck at 1 land drop per turn. If everyone else lands a signet turn 2, then they're all only a step behind but still focused on the guy that's ahead, and the downside of being the archenemy starts to outweigh the reduced Mana advantage. If two players get Sol Ring signet turn 1, they tend to focus on each other as they are each other's biggest threat, while everyone else is free to work together and build their board and deploy answers when needed. Most of this issues with Sol Ring "ruining games" comes from people freaking out when someone lands an early Sol Ring even if that early Sol Ring play may not have been we'll thought out (how many people keep shakey hands because they can drop a turn 1 Sol Ring?) when they should really take a breath, calm down, and play their game. I play a lot on mtgo, and I've seen plenty of people drop because someone landed Sol Ring turn 1 only for Sol Ring guy to lose anyway. I bet those dropped players thought that Sol Ring ruined the game, but it was really their attitude that did (for them anyway).
As mentioned previously, turn 1 Sol Ring actually reduces the chances of the player of winning. This is really significant, as the only chance Sol Ring has to "ruin games" is in the first few turns! The situations we are discussing, where Sol Ring helps fuel a large early Mana advantage, come in turns 1, 2, and 3. But here we are, when a turn 1 Sol Ring actually reduces your chances of winning, so it's on average a bad move to play it on one of the 3 turns where it can become a problem! What's going on here?
Well, for one, we've already discussed the archenemy phenomenon, and how that works to reduce the advantage granted by landing an early ring, even when connected with other Mana rocks or ramp. The key point here is that the real risk Sol Ring poses for running away with the game comes not from just landing a Sol Ring but from landing it in conjunction with other ramp, usually either turn 1 or with multiple other pieces of ramp turns 2 or 3. Your opponents playing archenemy against you, by countering that thran Dynamo or aiming their STPs at whatever critter you cast off that Mana, or casting an early reclamation sage to deal with a rock, helps keep this in check a bit, but it still is likely to snag a win, as honestly should be expected when you net multiple pieces of ramp very early, it's essentially magic Christmas land. Awesome opening hands happen, and will still happen without Sol Ring, and even without crypt and vault as well. The good thing here is that such games are usually over quickly (when the person who pulls it off wins, if they don't the game will take longer but that isnt really any different than a normal game at that point) allowing everyone to just shuffle up for another game, one that is highly unlikely to end the same way and much, much more likely to just play out normally. But there are also games where people just drop a Sol Ring turn 1 or 2 without the support of other ramp. This isn't as powerful as a lot of people think, not saying it isn't powerful but lots of people act like outside of cEDH this is going to dramatically increase your odds of winning as its a super powerful play and thus opponents go into archenemy mode when it might not be warranted and the Sol Ring player is more likely to keep a shakey hand or pursue a bad line of play because they overestimate the advantage that a turn 1 or 2 Sol Ring will bet them. Its this latter issue that I think contributes pretty significantly to that lowered win rate after playing turn 1 Sol Ring. The advantage gained from doing so without back up from other ramp doesn't really increase win percentages that much, yet people have a tendancy to keep hands that actually reduce their odds of winning because they can drop Sol Ring turn 1, or make risky plays because they get overconfident. And I haven't even mentioned that sometimes when the turn 1 Sol Ring player wins, it's not because of the turn 1 Sol Ring. I've seen people play it and it get removed, or their opponents stabilize before they can press an advantage, or they get archenemied and have to play defense all game, but then they manage to win from some unrelated thing, like hanging on after being taken down a notch and then mopping up the last few points of damage after a long game, or getting a combo later on, or hitting some big play on a turn when big plays are normal.