I remember when I worked for a registry (not a registrar) before the first launch of gTLD's. Bizarrely one of the products they were excited to promote was not to register domains under a TLD, but rather, to _block_ them. The idea being that if you wanted to make sure someone else didn't register <company_name>.[sucks, stupid, whatever] you had to pay them (Donuts) to make sure it didn't happen. It felt extortionate.
I worked on the .name application, and it was a key thing we were basically required to demonstrate we could do even back in 2000. ICANN was obsessed with protecting trademark holders.
I'll never cease to be amazed at what large companies will throw hundreds of thousands of dollars at just to _apply_ for a new gTLD. I mean what's the demand for whatever.superintelligence? Nobody is going to type that or notice it in a URL bar and think anything but "damn, that's a long TLD" while the dozens of other shorter AI focused TLDs sit there too.
Apparently it's still a thing. https://kb.centralnicreseller.com/services/brand-protection/...
If my counting is correct (the results wrap across multiple pages), 13 companies applied for the .agent TLD.