I always say: if I’m ever in a situation where I need a job and can only get one with a former employer - do I want them to say “hell yeah” or “hell no”?
I’ve worked with people who, if they had to ask me for a reference, I would decline to give one. By the same token, I would reject their application for a job in my company or team. And I have worked with the opposite - people who will always under any circumstances get help from me if they’re looking for a job. All the competence in the world doesn’t help if someone is miserable to be around.
Having contacts, people who are willing to give references and similar always helps. Sure, you can do job hunting hard mode, but why make things unnecessarily difficult?