> I do wonder however if they'd be better off using less l33t tech - do almost everything on Postgres vs consul and vault, etc. Scaling, failover, consistency, etc is a more well-known problem and there are a lot of people who've ran other DBs at tremendous scale than the alternatives.

In my experience people who ran Postgres distributed across a WAN tended to use obscure third-party plugins at best, more often a pile of dodgy Perl scripts. Using something designed from the ground up to be clustered seems to have a much better chance of working out than trying to make something that's been built as a single-instance system for decades work across the internet.