For some items fit and finish can be better if things are assembled with glue/etc rather than screws; and certainly a lot less of volume. Great as long as it doesn't need to be opened.

Keyboard, Trackpad, Screen are a mix of cost and taste. Apple has streamlined product offerings and each model has significant volume. Other vendors either don't have much volume (Framework) or get their volume through a multitude of models and options (Lenovo, HP, Dell), they can't justify engineering costs to get a touchpad made for them, and the Apple one isn't available. Thinkpads models have a spectrum of repairability, so Lenovo probably has some market insights there... they do tend to offer things in less and more servicable generation after generation.

Apple can do well on battery life because they own the hardware design, the cpu design, the firmware, the OS, and at least some of the userland and they have only a handful of models to work with. And they have a roughly incomparable product; it's always Apples vs Oranges, so they can decide to take a 1% perf hit for a 2% battery life gain... whereas if the Lenovo Ryzen Max 390 HyperFighting laptop is 1% slower than the Dell laptop with the same chip, that's bad PR, even if there's 2% battery savings.

Microsoft's own brand laptops could maybe drive better integration of OS and system, but really haven't. Microsoft is busy selling their Cloud, and stuffing Clippy into Notepad. I suspect they don't really want to compete too hard against OEMs anyway.