I believe FF/Chrome are using it.
I’m not sure if you’re trolling, or confused. I’m going to assume the latter.
Firefox uses Autoconf, but it’s stuck on a 20-year-old version. The bug report to upgrade to a modern version of Autoconf had been open since 2001 until it was WONTFIXed earlier this year. It does not use Automake: instead, it has a custom buildsystem that I’ve never heard of before, Mach. I don’t know anything about that.
I have no clue why you think Chromium uses Autotools. It used to use gyp, which was written for Chromium. Nowadays it uses gn, which was also written for Chromium.
Can you point me to any popular software that doesn’t?
GNOME uses Meson. systemd uses Meson. KDE uses CMake. WebKit uses CMake. Etc. etc. etc. You are on discourse.gnome.org, so you’re likely to find proponents of Meson here.
The accepted, commonly-held opinion here is that Autotools is really bad. Anyone who has been working on GNOME for longer than five years is likely very familiar with autoconf, automake, libtool, etc. and they were not very fun. We do not want to go back.
That said, discussion is pointless because everyone has their own opinions. Only thing certain is Autotools is way better than hand-rolled Makefiles.