The trick to working with this is that you don't need any of their custom Azure DevOps task types, and can use the shell type (which has a convenient shorthand) just as well as in any other CI environment. Even the installer tasks are redundant - in other CI systems, you either use a container image with what you need, or install stuff at the start, and Azure DevOps works with both of these strategies.
So no, it's neither hard nor impossible, but Microsoft's half-assed approach to maintaining Azure DevOps and overall overcomplicated legacy design makes it a bit hard to realize that doing what their documentation suggests is a bad idea, and that you can use it in a modern way just fine. At least their docs do not recommend that you use the dedicated NPM-type task for `npm install` anymore...
(I could rant for ages about Azure DevOps and how broken and unloved it is from Microsoft's side. From what I can tell, they're just putting in the minimum effort to keep old Enterprise customers that have been there through every rename since Team Foundation Server from jumping ship - maybe just until Github's enterprise side has matured enough? Azure DevOps doesn't even integrate well with Azure, despite its name!)