I do. In fact my next build will be mITX. I've had big towers for years, current 2x mid tower ATX have nothing but tons of wasted space inside, the cases are as large as many full towers. No real need for a mobo pushing 3x pcie x16 with a single gpu and onboard NVMe sockets. Just plain overkill and stuff that never gets used. Like running 2x sticks of ram in dual channel on a HEDT 8-slot mobo. Pointless.
Ppl claim there are advantages to ATX over mATX and mITX, and they'll be correct, if they are taken advantage of and actually used. Otherwise they aren't so much an advantage, but an unused luxury.
MATX motherboards can double the amount of case choices. ATX, you are stuck with just mid/full towers.