How do you source those parts? Figure out which part of the main board of your TV amplifier burned itself out with an electric meter, oscilloscope etc., and know enough about electronic repair to source a replacement resistor, capacitor etc.?

Sure, that's possible, and I'll give you that if you're manually soldering something on a circuit board that'll be a breeze compared to the surgery of trying the same thing on a modern phone.

My point was that for the average consumer without deep electronics repair knowledge the situation has become much better. If your $500 TV broke you weren't going to find a $10 replacement for its main board that you could pop in with just the skill of operating a screwdriver. But with modern phones you can do that with just a heat gun, credit card and a screwdriver.

Thus I think even though e.g. replacing the internal memory or CPU on these devices has become practically impossible, they're a lot more repairable in practice than most other electronics, current or historical.