I'm not sure what bike commuting has to do with this but yes, it's a 30 minute trip to the city centre from where I live and there's a bike lane the whole way. Living expenses here are lower than in the US but not dramatically so.

Pretty much all of those things (except bleeding breaks, but again just dont buy a stupid bike) are very easy to do. Fact of the matter is a bike mechanic is just never going to have enough expertise that they can command higher pay when the average person is just going to do the repair themselves if you charge more. Car mechanics aren't particularly well paid for that matter, and a car is an order of magnitude more complicated than a bike. You can take most of a car apart with a one ratchet set. The tools you need to do anything on a bike won't exceed a 100 dollars unless you go and buy all park tool stuff. The average person doesn't ride their bike enough for it to even need maintenance more than once a year. Basically that leaves bike mechanics with a customer base of enthusiasts with more money than time on their hands, at least in regards to where most of their work would come from. Used to like to watch this bike mechanic on youtube, I think he ended up selling his shop because fixing old bikes to sell them wasn't making enough money.

Idk about all bikes, but on my mountain bike with hydraulic brakes I replaced the line, filled and bled it just fine. Has been maintenance free for years. I did buy the tools for it, but it's not as hard as people make it out to be. Just gotta go slow and learn the process.

I don't see how it's an argument against finding a job in the trades that not literally everyone can do that. Not everyone can be a doctor either - doesn't mean you shouldn't chase that if it's what you want to do. Tons of people are more or less succesfully climbing the corporate ladder and have no desire to do anything else. This advice isn't for those people but the ones that are struggling with that or worrying that it is not AI proof - there are alternatives to it.

And yes nowdays I do own my bussiness but that wasn't always the case. I had a higher income as an employee. I traded that for more freedom and meaning.

There are some shady people in every profession, but most tradespeople aren’t ripping off customers too badly. It’s more like people who don’t work in the trades aren’t aware how expensive the operating costs are, like getting licensed/bonded/insured etc. Running a plumbing business is more financially complex than just buying materials and plugging them in to the clients’ home, so of course as a DIY homeowner you can skip a lot of nonsense. If you can do the work yourself, great! You save money and it gives the pros more time to help out folks who can’t do the work themselves.