DnD is not just systems though, its setting and its lore. even homebrew campaigns still benefit from the worldbuilding. I have played tabletop besides DnD/pathfinder including completely from scratch worlds - and worldbuilding is a toughest thing to handle, at least it was for me.
once you have a general setting full of locations, characters and events you can build around, then adjusting it to your specific campaign is much easier. and DnD specific setting and lore is something I was interested even before actively playing myself, so....
in any case, yeah, my cleric's initial choice of abilities is a full on card deck, but once I decide on my direction and narrow it down - I'm not using entire deck at any given time, so that too simplifies things. sometimes simpler just means you have to narrow down and specialize and work within those parameters within broader setting of many choices, not that there are fewer choices to begin with (when I say deck - this is what I'm talking about
https://www.amazon.com/Dungeons-Drag...dp/B08H1BQ2VZ/ , makes it easier to refer to specifics vs looking it up in a book and I know there is an app, but I find physical flashcards easier to use when at the table. my cleric who was my very first group based in person character - has official deck. my later characters just get home made index/flash cards)