same issue here, I am using 2k Acer monitor with MacBook Air m1 and I can get the maximum resolution with my monitor but with ant size UI and fonts, no HIDPI scaling options here.. shame

I have an Acer 2K monitor "G257HU" which worked perfectly with any windows machine, and I got my new m1 MacBook Air yesterday and it is my first Mac OS machine. from yesterday I am trying to find a solution for this scaling issue which works instantly with all my previous laptops and pc. can't believe I am wasting all this time just to adjust the UI to be able to start my work, and I didn't even find a solution yet. I purchased a usb-c to DisplayPort to try if the problem was in the HDMI cable but didn't work..