Depending on location, including availability to other options, I am sure it is doable. What do your really want out of it? If you just want a side hustle to give you a bit of spending money, and have the time and interest in working on others bikes, and you are a viable option for those looking to have work done, probably could work. How much do you want to deal with other people, how are you going to handle it when a customer is not happy, or when you screw up? I like working on my bikes fine, I make mistakes and it impacts only me.