you should check if the domain has been used for spam, PBN, changing niche, 301 or any other abnormal change or usage,
you should also double check with semrush (or ahrefs) for any spam/bh keywords or traffic as well as any sudden traffic drops that could be penalties,
compare the results with the wayback machine as well,
if some website is live for X year(s) in the wayback and got its traffic completely down or/and suddenly crashing then it's surely a red flag,
normal/partial drops while the website is still ranking for a decent number of keywords is acceptable, but totally vanishing from the serps is not accepted,
for me personally, i usually start with semrush, check the older traffic, keywords, etc...
that's easier to spot any kind of spam or/and change of niches/kws,
also if the website were ranking for some medium/competitive keywords, that would be a good sign of decent link profile/authority,
and if it's were not used/ranking for long time (4 years+), it's probably not a good choice,
anyway, you still have to double check the usage, link profile (links/anchors/websites, etc...)