> Our biggest problem today is we are a society of buying everything - so things cost more, we lose our ability to fix and repair things, ...

I'd phrase the problem differently:
Our biggest problem today is that people are hugely underestimating the future pain/cost that comes with choosing the _new_ and special products over the existing and more standard (and thus maintainable by oneself) old products.

The reasons are clear: companies try to maximize profits and thus do not want people to be able to repair/maintain anything. So they push towards more complexity.

Choosing the older and non-special product feels less rewarding to most people and more like a hassle, than just taking what's being put at the front of the shelf or top of the search results.

Bicycles are a good example. People should just refuse to use/buy bikes that need special parts/components which are not standardized (such that they can be bought from different companies).

If people want simple, maintainable things, they need to make the effort to look for these things and buy them instead of what's actively pushed to the market by the big companies. The effort will be rewarded with long lived things that cost less. 

 So true, the constant purchasing means people lose their ability to repair things, and companies have no need to make things repairable or provide parts. It's no wonder laws are now needed to force companies to make items repairable by users or other parties. And of course all the disposed stuff is even worse for landfills.