I find it somewhat hard professionally to get a role doing other stuff - I have brought up to multiple companies I have been at that I would like to do server-side work and work with other domains. Almost none of them initially take my wishes seriously, simply because they would likely have to hire 5+ developers to replace my expertise & productivity with Angular when I am on a roll (or maybe 2+ normal senior engineers).

Other companies aren't comfortable enough to allow me to do backend work when I apply, even if I have had non-professional experience working with [insert tech], or they would likely come with a drastic pay cut - I believe it is because I have become uncannily good at what I do on the frontend. Instead, I have focused more on moving up the ladder with other skills since I recognize that being a one trick pony sucks - I have leveraged my expertise to become a senior/lead engineer, that way I am shielded from that problem somewhat. A part of me does wish that I would be able to get more experience using other languages, technology, and domains within web development, because I like writing code & solving problems. This is a hard problem to me, and I have been taking the time to think about how to approach this in the back of my head.