Can't speak for Safari, but Firefox has never been anything but a dumpster fire for me. Constant reminders about updates and a UI that slows my computer to a crawl no matter what I do. Yes, I open many tabs and don't use a turbocharged laptop, but the same applies to my Chrome use with next to no problems, so really, fuck you Firefox for not adjusting after decades, as per possible user needs. Chrome seems to manage it, so why can't the Mozilla people with their own expertise and funds?

Many new versions and updates of FF that I've tried have claimed to be much smoother and more efficient, only for the exact same shit to start happening across the years and multiple laptops used.