In the first week of ownership, I ran into the issue that the LTE is flaky coming up from hibernate. Trying to debug that issue (spoiler: there is no fix) really made me appreciate how Apple is operating on a different level from other PC manufacturers. The fact is that Lenovo doesn't have the expertise to make an LTE card or write drivers for it, and neither does the company that makes the card for Lenovo (Fibocom). Fibocom takes an Intel reference design, buys Intel chips, throws the other components on the card, glues some Intel code together and ships it. Lenovo buys it and puts it in the machine, but doesn't really know how it works. When it doesn't work, it's not Intel's problem (they just make reference designs and sell the chips), it's not Fibocom's problem, and even though Lenovo takes responsibility, it's out of its depth in fixing the problem.
Compare Apple. They don't just take an SSD and slap it in a machine. They make their own SSD controller and combine it onto a chip with other functionality. Non-upgradable? Yes. But at least they understand how their own machine works.