For me it's just on launch. More precisely, the period before the application actually starts to launch. I guess it has something to do with mounting the various file systems and setting up the connections or whatever it is that it does.

I've had to install Chrome to try a thing or too (so not as a daily driver) and I haven't noticed anything weird during use. I've used Jetbrains' PyCharm daily for a few months and no problem there either (although that is a "classic" snap, not sure if it matters).