What's the purpose then of the IDENT function?

The ident function is for the controller - not the pilot.
Hitting ident temporarily deletes every aircraft from the radar screen
except yours!
So if I were a busy controller, watching a potentially developing
situation, and some dumbass entering the zone hits ident and wipes out
my screens for a few seconds - I'm going to be slightly less than
impressed.
It's kinda like hiring a carpenter, he's upstairs, you are downstairs
and you arbitrarily decide to switch on his power saw.
If he wants your help - he will ask for it.

Tony
--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE