If I was ranking each mode of "how much would I pay for this as a standalone card" in mana value (kinda psyched we're ditching CMC as a term, I remember thinking it sounded incredibly clunky all the way back in 2001) I think it'd look something like:
Silverquill: 1, 1, 0, 1
Witherbloom: 1, 0, 0, -1(?)
Quandrix: 1, 0, 0, 0
Prismari: 0, 0, 0, 1
Lorehold: 0, 3, 2, 2
I think this kinda shows that there are...not amazing. Of course, you have to keep in mind that you're getting 2 effects for one card, so that does make it somewhat better.
They're all pretty even, but I think my ranking is:
Silverquill is like a worse ojutai command. It's a sorcery, you pay a life for the draw, and the other modes seem pretty niche. Ojutai command kinda sucks butts but at least counter a creature is a lot better than sac a creature. This one seems like the clear worst to me.
Prismari I think people are way overrating. It's too targeted imo. 2 damage might be good but it also might be useless. Same for destroy an artifact. These modes are dependent on what your opponents are doing. Loot twice and get a treasure are just...so mediocre for the cost. If you've got a deck that explicitly cares about the graveyard (or treasure) then this could be strong but otherwise I just don't think it's going to be reliable enough, especially not at 3cmc. There are way more versatile answers for less mana.
Quandrix I'm kind of sad about because in theory it's one of the few recent UG spells that actually fits into Phelddagrif but it's still...eh. Three narrow answers that are, for the most part, weaker than just a counterspell, and the value mode is pretty low-impact. Answers tend to pair badly because a lot of the time, when you need to counter an artifact/enchantment, it won't be an ideal time to bounce or grave tuck, so you'll often fall back on the mediocre +1 counter mode.
Witherbloom is a little hard to compare because it's so cheap, but when I look at a fringe card like Grim Discovery
it's like...oh yeah that's probably just better. Killing some random mana rock or dork on T2 is really low value in multiplayer, and the -3/-1 is so narrow later, with the lifedrain being obviously very low impact though at least reliable. I could imagine the destroy clause is enough to make this semi-useful in a cEDH context maybe, but in an average game it seems too narrow to count for much. I still think it's ok because the land recursion is ok, and the removal modes will hit in a meaningful way occasionally with the lifedrain as a fallback, but it's far from an all-star. Paying 2 to get a land into hand is pretty atrocious unless you're defending a cabal coffers or cradle or something, and it's not even guaranteed to do that unless you've cracked a fetch (which is certainly not guaranteed on turn 2 when you likely most want this mode).
Lorehold I'm sure I'll catch flak for saying is the best, but y'know at least it does meaningful stuff. The indestructible mode is pretty versatile and could make a huge impact on the game by countering a boardwipe or turning a big combat. The sac + draw mode is some actual instant-speed draw in RW which mean you're not punished for holding this up unlike other board-protection spells. And lightning helix is some decent interaction which could pair decently with the draw mode EOT if you've got already got something to sac. The 3/2 is pretty meh but it does synergize ok with the indestructible mode and the sac mode, and could even be a decent way to blow out lethal math by making a blocker and helixing something to death. Not a card that'll always get played or anything, but at least it'll always feel like a real card.