You can workaround this issue by using the third party tool betterdummy (search on github). The tool is quite new and works fine on m1 and m1 pro (emulates HiDPI) However: I use a 144fps display and the underlying used private apple framework only supports 60fps at most. I am going to return my new macbook because of this. Why should I accept a workaround for a issue thats easily fixable?

For illustration (what the issue is and why the font looks washed out) I made some pictures with a macro-lens. On the left side you can see what the standard/normal output looks like (without HiDPI-Mode) and on the right with activated HiDPI-Mode (thanks to BetterDummy). On the left the "r" and "t" are stuck together. On the right "r" and "t" are cleary seperated by some pixels. Same USB-C cable, same monitor, same website.

As a reminder to everyone who is unhappy about the current situation with HiDPI and does not want to use BetterDummy: Apple is not watching this thread. They never will. The only way to reach them is to contact them via the Apple feedback form https://www.apple.com/feedback/ . According to the Apple Care Senior person who I talked to in the last days this is the only metric that is actively monitored/watched to improve their products. The form literally takes one minute to fill out. Thank you all!

As a reminder to everyone who is unhappy about the current situation with HiDPI and does not want to use BetterDummy: Apple is not watching this thread. They never will. The only way to reach them is to contact them via the Apple feedback form Apple Feedback form According to the Apple Care Senior person who I talked to in the last days this is the only metric that is actively monitored/watched to improve their products. The form literally takes one minute to fill out. Thank you all!