if you’re all matey matey with people you manage you’ll end up with big issues when one or another expects special treatment (there’s always one), makes a mistake or has performance issues or a tricky personal situation that affects their work .
Rather than focusing on making friends at work focus on being professional. The good connections will come.
I’m very friendly with my team but they also know that my priority is leading the team and supporting them to make their best contribution delivering the work. I treat them with respect and they do the same for me. It’s a hard balance to strike.