2019 Non JBL - what do I lose going with an aftermarket HU?

Was originally planning on going OEM Audio Plus but given the cost, I've started to consider the system I can build myself for the same or less cost. My biggest concern is; what do I lose going with an aftermarket headunit? I know I'd gain carplay and android auto, and all the other goodies; but are there any features in the factory deck that wouldn't be carried over to the aftermarket unit (assuming I used all the correct interface boxes and such)?

TIA, I feel like it was a bit easier in my 2013 that was just a matter of connecting the factory rear view camera and Sirius XM antenna lol.

 

so long as you do the maestro rr harness, you won't lose much of anything
the only thing i can think of is turn-by-turn directions on the gauge cluster display. music info still shows up fine. but I can't say that I've even looked at the display and scroll over to see if turn-by-turn actually works.

obviously if you buy a unit without dedicated Nav, you'll lose that.
If you want XM and don't buy the SXV300, you'll lose that.

with the maestro, all functions from the factory radio will still work (changing door lock functions, etc)