The new version of Sketchup is particularly slow to open. Many coolaboartors are impacted with this.
We use z240 or Z2 as workstation and previous version of sketchup where ok.
One exemple:
I just timed it, it took 4min 20 to open the file.
It’s a 50 mb file, but it’s almost the same with a file I was opening before of 1.7 mb.
It is also a documented “feature” that opening an older version file for the first time on version 2021 takes a longer time because of the conversion to the newer file format and the checking that this requires.