This isn't true.

I've got one person under me and have done for 3-5 years.

Most have enjoyed working under me (so I understand it), most resignations have been for bigger opportunities / bigger cities / bigger money (1 out of 4, and TBH I missed they wanted more money - this was my fault).

My current "report" seems very happy (though I expect them to leave soon, not for money but they are far more interested in another industry and tech challenges that come with it).

One person under you for 3-5 years with a four attritions in that period (this latest one being Person #5?) constitutes an incredibly high attrition rate. That’s worth introspecting on. Average tenure of under a year?!

It seems likely someone managing a handful of employees doesn't decide salaries. If his unders left mostly for salary reasons, I don't see how that reflects badly on him.

If you leave, can this report take over and be successful?

No.

They could do infrastructure, kind off, not code - no chance (I like them as a person but they depend on me to teach them how to code)

Hire "younglings" (star-wars) is my remit.