[2020] Can't save the game

Could definitely be the case. 32 GB RAM should allow you to get somewhere around 2-3000 assets. Reduce that number by 400 for each major DLC you have as they contain quite a lot of assets as well and you will get a sense of what you can expect to run fine with.

Ofc the size of assets matter since a small prop often takes up less RAM than a large unique building. The Loading Screen Mod can help you optimize RAM usage and shows you how much your game uses as it loads.