Keep in mind there is no complete feature parity with NPM. This only allows you to use packages not present in Deno's ecosystem, but it does not guarantee it will work flawlessly (and in practice it can be a pain to use some packages).
The best way to use Deno and take advantage of its benefits is to use Deno's packages. Allowing NPM packages is a good strategic move because on top of already being quite different from Node, there are not many packages, but it does not take away from how well it will work with Deno-native packages.
I like Deno. The benefits to me are largely around developer experience and tooling. I much prefer Deno's dependency management solution to Node's.
Additionally, lots of packages have made their codebase more runtime agnostic as a result of Deno existing, so there definitely are Deno packages out there. It just depends onw hat you're building!
Will there be a strategy to avoid NPM ultimately becoming the defacto package manager for Deno