do you want to post some screen pics of say, your mods folder? How big is your entire Electronic Arts Sims 4 folder? I have an Acer Helios Predator, I have a ton of games, I run my Sims4 game on ultra high, but when the entire folder for my Sims 4 game itself hits over 20GB, it definitely lags. I did a dumb thing and went on a cc spree against my better judgment and am using S4S to cull again.
In addition, if you use a lot of high-poly items at a time, that can make your game crazy. I have also noticed some save file bloat here and there, so I
backup my saves to my external drive and keep the ones I really want to play at that moment.
I also use BRU to rename my files to remove symbols. In addition, if you have more than .package, .ts4script, and zipped python files in your mods folder, that may also be a problem. I have seen mods folders with .jpg, .png's, html files, all kinds of stuff. Not necessary to play the game. back that stuff up.