I believe most of the spam comes from your email address being leaked by a company or website. Not sure how what your TLD is has anything to do with it.

I feel like this particular issue happens most often when one uses a catchall, as spammers like to try common usernames and this setup will allow all of them to be received.

In those cases, I found that it helps to use an obscure subdomain that doesn't have a website attached to it (e.g. mailus.example.com).

I would guess it makes it harder to recognize for website scraping if your email is left online somewhere.

A lesser-known TLD will massively increase the likelihood of your outbound emails being filtered as spam.