A highly personal question.
I don't think distance from property needs to weigh too heavily in your answer. This is really about preference. Also know that there are a lot of modern PM options that are more in the 10-15% fee range (as opposed to 30%). I'm talking about places like awning.com, key bee, etc.
I'm fully capable of managing myself. however I really like having a buffer between me and all the guests. The discount asks, the back and forth on checkin times, etc. I had much more peace in busy season and holidays just not having to worry about that. That's worth something to me personally.
I totally get that someone may hear that and say it's absurd to give away 15%, but my W2 job is still my main focus, and having a PM makes it feasible for me to keep my focus where it needs to be, and allows me to scale easier should I want to. It keeps the business fun for me, and not tedius. YMMV. I don't think you NEED to do one or the other. It's personal preference.