Straight from cold Fossa boot, until usable user interface:
Blender 2.91.2: 4 seconds
Gimp: 11 seconds
Boxy SVG: 22 seconds
Spotify: 43 seconds
The latter two seem like electron apps and take forever. Since these electron apps seem to be increasingly common, is there a way to speed up their snap load times? Spotify in particular is egregious.
This is not a direct answer as it isn't a way to speed up snaps, but it may help anyway.
Spotify is available as a .deb which you can install in Ubuntu instead of using the snap.
I tested both options on my system and got the following approximate results:
Snap -> 7.5 seconds
Apt -> 0.5 seconds
Which raises another point. You mentioned in a comment that you're running on a 2.5gb/s NVME SSD which suggests to me you have a fairly modern PC. I'm running something similar but I can load Spotify as a snap in 7.5 seconds compared to your 43 seconds. Perhaps you have some other issue on your system. 43 seconds does seem excessively slow on a modern PC, even for a snap.
