Nah, Deno is just another runtime. Now we have the browser runtimes and multiple server runtimes. Not to mention we also have server runtimes like Cloudflare Workers that are "almost" Node in the sense that they run on V8, but without access to filesystem APIs.

People will make sure to distribute their library so that it works on all of them. They might even use `deno compile` to bundle the library into a single file that can be consumed from any of the runtimes.