@grizzler SketchUp installs Plugins to the following path...
C:\Users\SomeName\AppData\Roaming\SketchUp\SketchUp 2023\SketchUp
If you go there when SketchUp is closed with your File Explorer you can rename the Plugins folder to ###Plugins (or any name you wish that doesn't conflict with existing folders). This means when you launch SketchUp none of your Plugins will load.
SketchUp will then see there's no folder named Plugins and it will create one.
So you now have a vanilla environment. If SketchUp launches without issue it is fair to assume your start-up issues are related to to your ###Plugins folder.
Now close SketchUp and go to C:\Users\SomeName\AppData\Roaming\SketchUp\SketchUp 2023\SketchUp and you will see a folder called Plugins and the troublesome ###Plugins folder.
You have the awkward choice of dragging dropping folders/files for extensions into Plugins folder in small batches to see when the startup issue occurs.
Or delete the recent Plugins folder and rename the ###Plugins back to Plugins then try hunt down the issue.
I'm experiencing similar issues where SketchUp won't launch and/or will get to Welcome Screen then fail. So I feel your pain.