I believe this makes more sense as a plugin, as whitewall wrote.
But I see why you are asking this. Actually, the plugins in Joplin do not feel so native: it's an extra sidebar that also does not exist on mobile, so it's not super convenient. I hope that with time, we can change this to become better!
Support for mobile is already on the roadmap it seems as makb wrote.
So for now, free to try the joplin-sheets plugin, I heard it's useful 