Good news!
It seems that Apple did it finally. New macOS 13 Ventura (I checked Beta 6 today) offers HiDPI resolutions for my QuadHD monitor Dell 24" connected to Mac mini M1. No need to use any custom solutions and tricks any more.
Hmm, just checked - I don't see any change in Ventura beta6 compared to beta5, but I might be wrong. Since Monterey 12.4 (true for all Ventura betas) halved HiDPI variants of all available LoDPI resolution options are there by default (so for example 1280x720 HiDPI will be available by default on a QHD display, but this is not really useful as it results in huge GUI elements even on a 24"). An other important change since Monetery 12.4 is that you
can create custom scaled HiDPI resolutions using display configuration overrides and these do work just like on Intel (they work in all Ventura betas as well). Therefore it is now possible to create custom HiDPI scaled resolutions manually by adding the right plist files or by using apps like
BetterDisplay (free functionality in the app),
SwitchResX (paid functionality) or some versions RDM (free, you have to build the app yourself). BetterDisplay also has a feature called native smooth scaling which gives you fully flexible scaling via a percentage slider (no dummies needed anymore).
@Aleksid1 - are you sure you don't have display overrides on your mac from previous attempts? Or is it only the 720p (and lower) HiDPI options you are seeing?