Regarding the upgrade being worth: whatever you upgrade you can move to a future bike. Just keep the old drivetrain. Like if you buy a nice 1x12 and in 2 years you decide to get a new bike or frame, you can reuse that 1x12 for that and just install you 3x8 back on this before selling.
Same with disc brakes, saddle, pedals etc.
This gets tricky with items related to frame standards like hub spacing. But the drivetrain isn't an upgrade specific to that bike.