Every connector pair has a side on which there are just flat pads, and one which uses some spring-like mechanism to build up pressure in order to make a secure contact to the side with the flat pads. These springs wear out over time and lose their "springiness", it's just a result of material fatigue, and having them on the easier-replaceable side (the cable) makes sense.

Thus, USB-C just made a different trade-off: they chose the design that would not mandate very tight quality control with regard to the material used for the springs, while Apple chose an overall mechanically more robust design, but with this particular weakness that it requires more quality control for the connector parts going into devices. They probably did that because they're the only ones manufacturing that part, hence they are able to ensure quality, which is of course nothing you can expect with an open standard like USB-C.

Except that in practice I've never seen a lightning device that stops holding cables, and I've seen a lot of broken USB-C cables and ports. Don't forget also that USB-C ports have a fragile tongue inside.