2024 Abjuration Wizard Lvl 10 Feature Spell Breaker

Basically, this feature guarantees that you can dispell any magical effect since if you fail you don't lose the spell slot.  10 tries a minute, 600 tries an hour...sooner than later you're going to roll a nat 20 and succeed.  So if you arent pressed for time you can dispell any magical ward ever lol no magical vault is impervious, no magical trap immune to disarm....etc

Am I missing any key details here?

Basically, yes, though a good DM is unlikely to let you just stand there and do that for hours without throwing any additional challenges your way. And you don't even need a natural 20, of course, since the DC is 10 + the spell's level; the most the DC will ever be is 19.

Bear in mind, though, that Dispel Magic only works on actual spells, not on magical effects generated through other means.

no, not really, you have not missed anything
PS, its actually 20 tries per minute cuz bonus action dispel magic