Txns are just hard in general but mature RDBMS have spent a huge number of man-years on getting it right. After the time I've spent on Couchbase, Mongo, Elastic

Txns are just hard in general but mature RDBMS have spent a huge number of man-years on getting it right. After the time I've spent on Couchbase, Mongo, Elasticsearch, I doubt I'll ever use something non-transactional for anything OLTP or OLTP-adjacent. If Postgres or MySQL can't scale up to handle it, make them...or get a new job. Scale is a PITA.