I have investigated a bit more the topic introduced in Joplin (Portable) on Windows weird start time - #2 by tomasz86.
Unfortunately, I can no longer reply to that thread, so I am starting a new one.
The "problem" seems to be related to the operations run when the executable of an already running copy of Joplin is clicked. Those operations appear to be different from those run when the tray icon is clicked.
Could we have a Windows version that skips those operations if Joplin is already running?
(I do not know whether this is a bug to fix or a new feature to implement)
Thanks
P.S. to reply to the last message of that thread:
No, the problem is not with the hardware of with some software, and all other Electron apps are running normally.
Moreover, as mentioned in the first message of that thread: if opened from the tray icon, it opens instantaneously.
It is just something that has to do with the way Joplin starts when you run it from its executable (see above).