Based on my experience, I would have to disagree. What's NOT to need in a digital mixer?? While you MAY NOT use all of its features up front (and most don't), the expansion/growth capabilities coupled with those features is the key driver for me.
I used to have your [apparent] mindset before I started working on digital (X32, QU, M7CL, etc.). It's what you get used to, and NOW I'll take digital any day over analog. Why?
Firmware upgrades, routing options, built-in effects, scene save capabilities, onboard effect and instrument libraries, remote mixing/personal monitor (IEM) and expansion card capability, recording, etc. are all part of that.
Yes, I still use a Mackie VLZ for personal use at home, but for gigs.. give me digital PLEASE!
It shouldn't cause thermal issues, but I'm with you - for different reasons. The included amps give you NO flexibility on power output, often shared with a monitor mix, and not bridgeable. The cost is less, but you get less for the $$ IMHO. Used too many of them that give you no options when one needs to finagle a mix or something one hadn't planned on needing comes up.