The only organization that can grant gTLDs (specifically the part after the . in a domain name - .com, .net. etc) is ICANN - and the process takes a lot of time, and money.
You have to apply to be an owner of a gTLD (global Top Level Domain) - and if accepted, you have to manage it and handle everything yourself.
This is only typically done by large companies or enterprises, because the cost (as of writing) to even apply to have a gTLD costs 227,000 US Dollars - definitely not in the budget of most individuals!
The pricing is definitely intentional - ICANN doesn't want to pollute the gTLD namespace with tons of names. The original intent to limit gTLDs to what they were before was largely to help prevent abuse and confusion.
I understand your interest, so if you want to learn more - a great place to start is here:
https://newgtldprogram.icann.org/enHowever, somewhat unrelated to the original question - it is more realistic and obtainable for people to get IP space and own that, than it is to do this. That depends on your country, for most of North America, that org responsible is ARINN, for Europe it is RIPENC, and for Asia it is APNIC. For all other regions, check here:
https://www.nro.net/Obtaining a ASN is the first step, usually for not too much money. Second is applying to obtain IPv6 addresses (which is usually free - including to obtain), and maybe leasing some IPv4 to start (purchasing a block of IPv4 is expensive, usually in the thousands of dollars minimum).