One of the biggest advantages is that a lot of people in the business are already comfortable with the ecosystem. I know that from the perspective of HN that SSMS, pgAdmin, DBeaver, DB Browser for SQLite, et. al. are mostly isomorphic, but from the perspective of everyone else in the business, these are substantially different things to think about.
Whether the popularity of the MS ecosystem is good or not is a separate problem. If we are solving for "make the business go well and I get paid more", the strategy is usually obvious. We can still advocate for OSS and not-so-many-eggs in the Microsoft basket while we get paid for using these technologies. Again, SQLite is the preferred engine in my tool belt. I don't want to have to manage a hosted sql machine. But, sometimes the problem absolutely insists upon it.
Also, if you are using C#/.NET, integrating with MSSQL is always a little bit easier than the other providers. SQLite (and some others) have lackluster types for things like time. MSSQL has DateTime2 and DateTimeOffset that map exactly into the CLR types.
I don’t mean to be annoyingly contrarian or argumentative with this statement: I’m definitely not convinced by both of your comments on this subject.
“Comfort” is not really a tangible benefit.
For example, I am personally very comfortable with Chef software for configuration management of VM-deployed applications, but I am quite aware that my own comfort doesn't make it a superior solution versus containerizing applications. We just have Chef around because that’s what was chosen 10 years ago.
Obviously, developer/ops familiarity is still valuable, I don’t mean to say it’s not, but there is a point where the band-aid needs to be ripped off.
I have a hunch that all these great tools that make MS SQL convenient are more like band-aids to a mediocre experience. E.g., RedGate replacing multi-million dollar consultancies sounds great, but what’s even better is not needing a multi-million dollar consultancy in the first place.
I will also give you the context that I used to be a defacto DBA for MS SQL. That doesn’t necessarily mean I know what I’m talking about, but I do know that I personally do not miss SSMS or any of the Microsoft ecosystem.
The whole vibe of that ecosystem is “put your life in Microsoft’s hands and do everything Microsoft’s way and we hold your hand and make it easy, except that making everything easy for everyone causes everything to be massively complicated and brittle.”
I still occasionally get StackOverflow notifications for an answer I wrote which was just “try restarting Visual Studio” and even though the version I wrote it for is over a decade old I still get comments that say “this worked for me.”