mentor them, teach them, find what their problem is and help them with it

if you can’t improve anything, then as last resort help them find somewhere else

i know that’s easier said than done, but i’ve done it, it’s possible for sure

(for someone who is openly destructive or hostile, well that’s of course different)

It's pretty standard in Western European countries. The employer must primarily provide training or arrange another, more well-suited position in the company. Even as a committed leftist I find that in some cases the rules are too strict, for example when it discourages small companies and startups from hiring more manpower.