I usually call them management games. Looking at the Steam tags for Factorio and RimWorld, they both have "Management" and Factorio additionally has "Resource Management". But I think "Management" is your best bet.
I think RTS games don't usually fall under management and instead are just called RTS.
In terms of my favourite ones, I love FTL: Faster Than Light. I'm picking it up again at the moment actually. I also like RinWorld, Oxygen Not Included, and Dungeon of the Endless.
I don't know if I would call FTL a process optimization game. One thing I feel like it's missing is feedback if your process is being optimized or if you just got lucky. With Rimworld, Roller Coaster Tycoon, and Factorio all include metrics that allow you to judge if you've made your process better but because of FTLs randomness, it's hard to determine if you played better or just had better rolls. That said I love FTL and it's an amazing game.
Absolutely how I felt. It's heavy on the randomness and I've never beat it despite doing very well on some runs. I think the important thing about FTL is that it's about the journey. The ending is always depressing.