Strongly disagree. Rxjs is such a better async pattern than anything else in the javascript ecosystem. The front end shouldn't care what node is doing, especially since not everyone's front end uses node. What I don't like about async await is it changes the pattern you are seeing, intermingling synchronous and asynchronous code based on the correct placement of a keyword, then using try catch blocks to catch errors are just so ugly. Passing my data through a stream of pure functions that transform the data into what I need just feels pleasant to work with, but I do agree it takes awhile to be proficient in it.

Use NestJS, you can have RxJS and Angular in your backend

Doesn't Node.js mainly flow on callbacks?

As far as my experience goes, promises require some extra work too.