I was wondering why the calculator took so long to start on 18.04. I thought there was some problem with my system.

Doesn't bode well for 20.04. I've been with Ubuntu for a very long time, I like that it just works most of the time. May be time to try out another distro if all the applications are this sluggish.

Ah, this makes sense now! I've always wondered why the calculator (of all apps) was by far the slowest to start on 18.04 for me.