Why?
I don't think Lemmy is the platform that should be used for following individuals. It's not Friendica or Mastodon or Pleroma or (etc.), it's a link aggregator for topics and communities. I personally believe celebrityism should be avoided.
If you really want, you can already view /u/ pages and you can probably make an RSS feed of them. But the idea of following a users isn't really what this software should encourage.