I don’t know, nobody needs more the 640k of RAM, right?

Maybe you have multiple modules, and depending on the configuration the routing changes. Or feature flags, that enable a breaking api change. Or a stupid customer that pays you a million dollar for custom routes.

But what benefit do the attributes bring? You need to learn them by heart, on builders Intellisense can help you.

Well yes - if you need some kind of dynamically configurable routing then attributes aren't a good fit. I like the fact they are there right next to the relevant method...

Another thing is, that attributes totally opinionate your code. You pull in a framework into your code.

If you - for example - write one controller you want to use with multiple frameworks (ASP.NET Core or Nancy), you need one controller per framework, just for the attributes.

I always found them more annoying then helpful. Most people seem to see it that way. Most frameworks are moving away from attributes for a good reason.

CMS:s do that! Any kind of editorial content being served is a use case.