Yes but usually you’re not expected to be an expert in all of them. The database and Linux part are expected competencies not expert level.

A decade ago it was possible to be a true full-stack developer that kept up with both ecosystems. Much, much more difficult to do nowadays. Hence the explosion of “frontend engineer” positions.

I've been around a long time. I don't think it's any more difficult than it used to be. On the contrary, I think it's considerably easier -- everything comes with source code and all these new fangled frameworks are practically the same anyway.

Back in the day we had client server architectures and it was exactly the same thing. Even more tiers would sometimes be added and there were frameworks for all of them. We didn't get source code. The frameworks were full of bugs. There was no stack overflow. Documentation usually consisted of a few trivial examples. You just had to hack, hack, hack and figure out how it worked. I remember when Swing came out and being very excited about being able to work on something that wasn't completely insane for client stuff (that's how bad it was ;-) ).

This is just the life of the computer programmer. If you like learning new things, it's never a dull moment!

It's not any more difficult than it once was. You don't need to write a mico-servicized containerated whatever system right out the gate just because that's the way some people like to do it at scale. There are tons of people out there making bank off of sites that are just highly customized wordpress instances, after all. You've got to use the tool appropriate to the job. Certainly today the high end of what's built on a regular basis in terms of web apps is a lot higher than it used to be, but if you have a need to support that level of traffic you either have the ability to hire a team of devs or your business / monetization plan is dysfunctional.