It is fine, but not good enough. No usb c front header, no wifi, mediocre VRM and it's cooling...
I still don't get why mATX didn't become the mainstream. Most of the people will be fine even with ITX boards (they just need 1 slot for GPU and nothing more), a few of them would need an additional slot for eg. a sound card and again - mATX will be more than enough... And yet we're stuck with a "relic of a past" standard (when each function of a PC had to be added by an expension card - sound, LAN, GPU acceleration...) that just takes more space and giving no profit in return.
The lack of popularity of mATX may have to do based on demand. There has been always a higher demand for ATX over mATX boards, especially in the DIY market, which is why motherboard manufacturers focus on that size. I am unsure if today's OEMs still use many MATX boards in their desktop builds like it was a decade ago or so.
I share your same thoughts about mATX, which I like that size option. I went from a z77 Asus Maximus V Gene to a MSI B550m Mortar (non-WIFI). It is a great board that satisfies my needs. Buildzoid did a power summary of the board, which he explained has a great VRM. The ASRock X750M Pro4 has a weaker VRM and other issues that I have researched, which I avoided. Instead, I waited for a long time until B550 offerings started being released to the market. The only downside to the B550 is the chipset limitations itself, such as the second m.2 slot is pcie gen3 instead of gen4, which the x570 does not have this limitation. For most people's needs, pcie gen 3 for m.2 nvme drives is enough. One would think mATX would gain popularity as integrated devices (e.g. audio, networking, etc) have gone a long way over the years, thus the lesser need for pci/pcie slots.
If you are still looking for a decent mATX for AM4, check out the MSI B550m Mortar board if you have not already. It does have usb c on the rear i/o, usb 3.2 gen2 header, wifi option and a great VRM. I am unsure what other requirements you are looking in a board, but I wish you luck in your pursuit. If you have any questions about the Mortar board, feel free to PM me.
