I would reinstall all the games fresh.
I have gone through the same evolution as you a few times and I have got several harddrives in my system that I could simply remove but I use them to copy and move directories such as downloads, pictures, documents etc and then I can move them back to where they belong. Saves a lot of time and provides some peace of mind. But when it comes to games and such I simply reinstall them clean since all the save data is in the cloud usually so you do not lose any progress. Another thing that I do is write down on a piece of paper what other programs I have so I dont forget which ones I use so I can
download and reinstall them. Once installed make sure to check for updates and drivers to all of the components including the motherboard, monitor firmware and so on.
Good luck with the process and definitely reach out if you need any additional help.