Oh wow, where do we start there.
At first, both CRPGs and FPS games have absoluetly same roots. You maybe don't know, but first game that can be called "FPS" was game for Plato computer, where it was first person dungeon crawler with turn based shooting.
Part of this early simulators, strategies and CRPGs is developing what for 80s and 90s and early 00s will be known as Computer Gaming Industry, separating from console one because it was ideas and executions of enthusiastic teams and even people in their basements, that then will grow in companies, unlike console ones, where it already was big corporations that from start selling games for profit only. For second, this computer games tried to achive making something opposite from arcade games - absoluetly majority of games on Arcades, that then was ported to home computer systems popular like Commodore VIC-20, Apple II, Atari consoles was primitive arcade games with most simple gameplay - like asteroids, or static shooting ranges, or platformers where you need just press keys to hit max score, tetrises and scrolling space shooters.
Plato games where people tried to transfer their favorite tabletop games experience, strategy experience, adventure ideas builded new way of thinking, where with current technical limitations they tried to make far more complex and advanced, and even in 70s it was prooven to be possible.
In mid70, students with their univercity computers made things that was in many ways, beyond limits of ideas of common very primitive and limited arcades of this time. And it will not take long time, when this ideas and concepts from Plato computers will transfer to growing market of personal home computers.
They also proved something different - that while you can transfer elements of system to computer, Computer RPGs will never be same thing as tabletop for many and many reasons - and main mistake where people count tabletop RPG games and computer ones as same thing because "they both using roleplaying system". In tabletop games it is most times actual unlimited adventure, where interaction between people and their story they create is main thing of gameplay, when role-playing system serve as "instrument", set of rules that helps people have concretic adventure, not just cashul talk with no point. In video game, where computer is your gamemaster, it can offer far more complex RPG systems and more heavy mechanics since you don't need to throw dices or count all your stats by pencil, but also computer can't in proper interaction and building story on run like real humans can. So worldbuilding, balancing, plishing gameplay and creating new, modified and appropriate roleplaying systems that usefull for computer adventure become main point of CRPG development. And ultima 2 is example what happens if you just take your bizzare tabletop adventure and brainlesly transfer it to computer.
CRPG games, Stategies and simulators, Adventure and quest games become main builders of new, user-based game industry where it was no longer based on millionere multicorporations with their locked hardware and aim towards children audience. Consoles always was aimed by companies back then as toys for kids, while computer systems was hobby of highly educated technical students and both audience and creators represented it. Only bizzare thing is japan, where they started heavely copy and port early CRPGs and then merge them with with their visual novells which result in JRPG but this is another theme.
Following to more late time, 80s and 90s was golden age for CRPGs, where new computers made it possible to evolve them in all directions. Games like Might and Magic 1 become first fully openworld fully first person games. Games like Ultima 4 start offer complex worlds beyound RPG systems and sets of rules, with its heavly morale-balesd game mechanics where you need to simluate life of saint in builded dynamic world.
Even Wolfenstein 3d, which oftent refferenced as fitst "popular" FPS game grown from RPG games too - in 1990 Carmac was surprised by awesome demo of Ultima Underworld game, and builded his own raycast engine which was far more inferior. His game Catacomb 3d is basicly maximum simplified arcade version of real-time dungeoncrawler with most primitice "click" gameplay, same goes with Wolfenstein 3d, doom it just become popular as simple "half-freeware" games, being in all ways inferior both technical and gameplay to almost fully 3d Ultima Underworld, that offred limited by size, but filled by factions, characters, dialogues content and with heavy RPG mechanics that was combined with real time gameplay. Ultima Underoworld become father and mother for all modern FPS games, same as for ARPG genre that evolved with such clones as TES Arena and Daggerfall and differend mixed sucsessors like Raven's softaware experements of mixing action and RPG, and direct spiritual sequels like System Shock.
Still, to this date many and many CRPGs suprised me by their way of worldbuilding, ideas and gameplay, their advanced for time graphics and way of thinging. It mindblowing to know that same time as on normie-people market dominated games like primitive platformers and Beat-em-up, there was even more graphically advanced games, that tried to simulate whole worlds, real adventures and heavy roleplaying systems, with their atmosphere and narrative.
For me, I tired of arcade and modern games. Current market eaten by console-style games, that taked from computer ones minimum to not become absoluetly arcade and thats it. I don't find any interest in so called "RPG" games based on hack-and-slash and linear cutscenes, same way as I become tierd from games where plot and dialogues is main thing. What I want is complex RPG system - like Wizardry 6 one or Daggerfall, which be impossible in any pen and paper games because way they builded, and game that give me actual RPG chanllenge - where combat, exploring and character creation and building is main tasks for player. Same way as I like more early western science fiction and fantasy, where people get more wild imagenation and did things which modern "boring" fantasy most times can't allow because current audience will now understand.