It's not the be all end all though. A lot of the domains listed are not usable by most people.
If you've got a script searching for available domains you don't really want it wasting time searching dictionary words on *.accident-investigation.aero as they'll probably all flag legit, meaning if you use the DNS lookup then whois method you've wasted a lot of time searching for domains you can't have.
Re:The Public Suffix List
by robin_reala on Thursday August 18, 2016 @09:50AM
(#12312429)
This list has been maintained for 9 years, if there was any leveling that needed doing it happened a long time ago.
This list may help to level the playfield between domain grabbers and legitimate domain users.