(at least on intel, I’ve no looked into it on AMD’s side)
Intel ME can be neutered. On newer gen’s doing so can be as simple as setting of a single flag. On older systems you can rip so much of it out that all it can do is bring up the CPU.
I would say you can still be concerned by IntelME (as it has been shown to be exploitable) but still purchase Intel/AMD. I mean who else you going to purchase from if you want an affordable x86 system?
ARM is getting more mainstream (in the laptop/desktop/server world.) and we now have fairly decently powerfully desktop/laptop arm powered machines we could actually dev on but the ARM world is still filled with binary blobs needed to get the cpu started.
Power9 has a ton of open source but the CPU’s are not. RISC-V is promising but still pricey as hell atm.
Just saying, you can be worried about ME but in a place where you are stuck with it.