Fewer than 100 will massively pig out memory, on Android, Linux, and MacOS, for Chrome, IME.
My main FF instance has ~1,500 tabs FWIW, though I'll often bypass those for a given session by running incognito only. Even then I'll easily hit 100+ tabs in only a few minutes.
Ive run chromium and firefox side by side for years to isolate personal from work. The only noticeable difference is Chromium crashes when it uses all the memory.
People's overwhelming fascination with Chrome escapes me. Some subtle detail seems to make it stick out. Everyone remembers that one time ff crashed on 2005, but gives berth to Chrome crashimg every few days and selling their personal data to google.
Oh yes. And you don't even need that many tabs open for Chrome to eat half of your RAM.