Having experience with both, with small-medium size DB, they have pros and cons. MSSQL wins on ootb tooling, easier monitoring, collations, better query planner, ootb encryption, ootb data compression etc. I have seen running more than 100 databases of hundreds of GBs on a single MSSQL instance without a problem. I heard stories about data corruption, never happened to me.
Postgres wins on (lots of) datatypes, indexes types and plugin ecosystem, eg Postgis is great. Per process connection is meh, but can be mitigated. It loses a lot on all features based on operating system libraries, different OSes give different results, not great, not at all. Also if you are using postgres at enterprise level, better have some kind of support, which may cost a lot.
So far I had less issues with MSSQL than with Postgres. YMMV, ofc.