iMac experiencing slow startup, multiple software issues after Ventura 13.3.1

I experienced the same issue immediately after 13.3.1 update, but with more adverse problems. Frequently, the iMac (Retina 5k, 27", 2017) will startup and hang on an all black screen, all yellow screen with a cursor, or checkered magenta/white display. Also, experienced the Apple logo and progress bar show enlarged and skewed on the right edge of the display. Enough combinations of NVRAM resets and booting into Safe Mode eventually lead to successful normal albeit slow login. Unrelated or not, Excel started to crash on launch and needed to be removed and reinstalled. The iMac has been hanging since first upgrading to Ventura last fall, especially with Adobe CS apps. An issue that was not present before. May downgrade to Monterey. For now, I will avoid any restarts until the next update.

Ventura is now up to 13.6.1 which had some security components and fixes. I suggest you update to that and see if the problem persists.

I think the suggestion to disable One Drive and Google Drive is the best test.

Mostly looks like you picked up some problem with your two cloud services, perhaps Internet, cannot tell for certain.

You can use Drive DX to possibly get a better view of Drive health…

https://binaryfruit.com/drivedx

Thanks to Jack-19…

It may be wise to run SMART Utility to check the drives' health. 

Anyone having frequent issues with Ventura 13.3.1 and Illustrator 2024? My last version of Illustrator became slow also, but it's worse since upgrading. Crashes on opening a file, and I have to force-quit often. Any recommended clean-up or optimizing procedures?

I think you should disable OneDrive, Google Drive for a test.