A local bike shop repair has two benefits over doing it myself - experience and convenience.
Unfortunately for bike shops the people who are most in need of their experience are those who are newer to riding (or dusting off a 20 year old unridden bike). When the workshop labour charge is approaching the perceived worth of a bike the customer is not going to want to use those services (more likely to dump the bike and buy a new one from a sporting goods store or Walmart).
People who ride regularly are more likely to have bikes where the cost of a repair is a small fraction of the bike's worth (personal or actual) but they are also more likely to have the tools and experience to do the work themselves.
I go back into mtb riding 2 years ago and upgraded to a mid-range full suspension bike at the end of 2019. While I was familiar with basic bike maintenance I didn't know what I was doing with some of the newer bike tech. When my bike needed a service in the summer I tried to use my local bike store - they needed my bike for a month in order to get the work done (backed up due to Covid demand).
Rather than miss all those rides I bought the tools and figured how to do the jobs myself. Now I have the tools I can do those jobs again for almost no outlay (and wrenching is therapeutic).