"So when was the last time you actually replaced a SSD, battery or some other internal on a laptop?"
Two weeks ago. No, I don't work in IT for my company, doing this to broken user machines. I do it for myself and for friends. In the past two months, one friend got extremely annoyed with a Mac from several years ago which is still fast enough for their use cases, but had a battery that was worn to the extent that they were tethered to a wall. Fortunately, this was from when Apple wasn't gluing things down, so I got them a replacement and spend a few minutes with a screwdriver. Their computer is good again and for much less than it would cost to buy any replacement, let alone the same model from Apple's current line. Then we have the two weeks ago situation where I removed a disk from a laptop, in this case because it was not turning on and accessing the data was going to be faster if I read it in a different device than if I fixed the problem that developed.
Sometimes, I do this for myself, but the fact that I'm doing it for friends and family proves that there is demand there for doing repairs. By making the repairs easier, we make it possible for people to do them on their own without needing an expert or to hire the assistance of someone who doesn't need extreme equipment to manage it. Contrary to your statements, cheap laptops are not usually built so badly that you have to break them to open them up, and if they are, the chances are that they were among those that weren't intended to be opened, which is exactly the problem.