krunner should work, so alt+space should open krunner box. Type plasmashell there and it will find plasmashell process that you can start.
This way you can open any app or find a file, so even if plasmashell is not functioning, you still can do basically almost everything.
Is plasmashell crashing all the time or maybe only after the boot? Or maybe occasionally?
I don't think that in this case hardware matters. Plasmashell or any kde component being crashy means in almost all cases a wrong config file.
If you create a test, default user and log in, the issue will not be there.
Do a copy and delete this config and relog the session:
cp ~/.config/plasma-org.kde.plasma.desktop-appletsrc ~/.config/plasma-org.kde.plasma.desktop-appletsrc.bak
You will land in default desktop without a wallpaper and with default Plasma panel. But your latte will be there, so it may double the panel (in your case the panel will be behind the dock, but you can easily remove it).
Anyway, if this config was at fault, plasmashell will work again and you can just config the desktop again.
If this didn't help, try other plasma configs. The same way, first do a backup file of the config, then delete the current one and relog session to see the changes.