Which browser do you use on MacOS?
Safari mostly. I prefer the incredibly minimal UI and iCloud integration. With some Userscripts and an adblocker like Wipr it's smooth sailing.
As a backup I use Firefox modified to look like Safari: Safari Firefox Mod - https://github.com/AdamXweb/WhiteSurFirefoxThemeMacOS
Not Just Third-Party Apps: Reddit Experimenting with restricting logged in access for mobile web users...
Link to a thread where user is in panic over inability to log in on mobile web browser but is assured by reddit admin that is an "experiment"
Mentioned on this Ars story
Google is getting a lot worse because of subreddits being private
Try Searx. It is a free, open source metasearch engine so it gets results from other engines. Albeit much more privately than accessing those services directly.