logic says that if 2 domains have the same strength (ie DA in this case), but one of them has 10k backlinks while the other one has 30k backlinks then - by logic - the one with 10k backlinks has better links, therefore it's better.
But this assumption is superficial as we don't know everything that's important about these domains (their trust and reputation with google, their backlink quality and anchors, their content history, etc).
It's possible, therefore, that any / most / all of these things apply to either / both domains, which could make either / both domains bad or useless:
- the 10k links domain is penalized / banned by google for whatever reason (had been flagged as PBN, is using abused anchors, had been used as casino redirect, etc), thus making it impossible / hard to rank in google (therefore being considered useless by most SEOs)
- either domain could have trademarked words in it, which would make it hard / impossible to monetize despite of its high DA scores
- most / all important backlinks of either domain could be nofollow / non topically relevant, which could make it weak as 301 / money site
I really don't think we can ascertain the quality of these domains based on the few metrics you've shared, so more in-depth analysis is needed IMO...