Yes the fact that you don't use your country's tld is a uniquely USA thing. I lived in Italy, UK, Australia, Brazil, Thailand and Indonesia, in all those places the national tld (e.g. ".it" in Italy) is the most commonly used. Even American services usually have a localised version with that tld, e.g. google.it; Some American email providers offer local tlds as well, e.g. I used to have [username]@hotmail.it
I'm curious about the situation in the UK. They don't seem to use ".uk", but rather ".co.uk". I bought a couple ".uk" domains because they were cheaper than all the other weird ones like .club, .today, etc. I couldn't figure out why a well-known place like the UK would have deeply discounted TLD's.
Many countries mainly use second level tlds, e.g. co.uk, gov.uk, co.th, com.au, .com.my, etc. because the registry of that country decided to make those available to the public, and the first level alone is not.
In some cases the first level tld subsequently became available to the public - for example in 2022 .au has become available, but the original second levels, e.g. .com.au or .gov.au remain more popular because the public is more familiar with it.
