I may be cursed but I have never experienced any slowdown with Firefox. I never noticed the appeal of Chrome, but have I only used it twice in my life…
I use a macbook for work. Chrome is ridiculously buggy and sucking every bit of memory. Firefox is almost as bad. Chrome is really bad when using more than 1 tab. Firefox has rendering issues with jira and git. Chrome compelling locks up when using meet, Firefox is slightly better.
In my opinion all browsers have sucked since 2015. Slow, unresponsive, rendering issues, resource hogs. Overall the browser experience has led me to use the internet less and less. It is not the privacy, it is the basic functionality is not working consistently.
Damn, how old is that MacBook? I think you should ask for a hardware upgrade, because both Chromium based browsers and Firefox don’t use too much resources and run smoothly on the newer models. I can’t say that Chrome isn’t buggy, as I barely use it, but I have never encountered a Firefox bug on any of my devices.
macOS is a desktop OS. It has a terminal, it lets you download that sketchy .app file from a random website, and it allows browsers to use their own engines. So, not too different from Windows or Linux.
You are correct for iOS and iPadOS though. They must use the WebKit rendering engine. All browsers on those are just Safari reskins.
It works really well on mobile, that's just about all the appeal I can find. Some sites are a bit glitchy on Firefox, but it's really rare. I keep it around for those occasions. On PC it's just Firefox and Edge (cuz work).
Every day a new article comes out that slowly convinces me to switch. Chrome's profile switcher was light years ahead of Firefox last I checked, but I'm going to have to check again and see if that's still the case and if so, what I can do to cope.