Why should you prefer this named type over the literal syntax?
What benefit does it give you?
Why should this be a standard?

Please add some more information justifying why such a rule should exist.

I feel like generally this is a better, more clear way to do it. It's just a stylistic preference. I think its more clear and uses a native typescript type. Readability really

There are plenty of other "preference"-based rules so I don't see why this wouldn't be one

Generally now-a-days we don't look to ship rules for stylistic preferences unless there's a really, really good motivating reason a codebase should standardise or if the community is really rallied behind a stylistic decision.

For niche cases like this where it's a purely stylistic personal preference that is also very niche - we don't look to cover it with our plugin.

Instead you can use general purpose rules to ban the undesired code as per this FAQ: https://typescript-eslint.io/troubleshooting/faqs/general#how-can-i-ban-specific-language-feature