Not sure about the current state of affairs. But I think for example MySQL had json columns way earlier than mariadb, and to me they appear to have a nicer design/accompanying functions to work with them.

Also, I've run into a deadlock issue a while ago with mariadb. Skimmed their bug tracker and there are a couple similar reports, some remaining open, other getting fixes like "well I changed stuff around and I think it might solve the issue". An emerging pattern was that they think there might be a locking issue, but they're not sure, and any deadlock they can reproduce under rr (or whatever that recording debugger is called) is, according to them an issue with rr itself and a false positive. It gave me serious "we're just yoloing it" vibes. I understand it's not a trivial code base and they're probably understaffed, and I still prefer it over MySQL merely because of who owns that project but still, it left a weird impression.