My laptop i7, 8GB RAM, worked fine with Illustrator and Photoshop version 2018. I recently installed version 2020 and started having serious problems with RAM. Even just an open Illustrator without an open file consumes 2GB, although earlier it was no more than 400 MB. If you open Illustrator and Photoshop at the same time, the laptop starts to frankly freeze, although there hasn’t been such a problem since 2018, I could also open InDesign at the same time. Tell me what has changed in the programs, what memory is not enough?
As you can understand the software uses more advanced features and will always require a good spec machine to be able to run the software well. That goes for all the other software mentioned as well and when you are using them all together you must understand that the higher the spec machine the better they will perform.
You can also see the release infomation here to see the things that have changed since the 2018 version.