So the intel era is not Apple products? Butterfly keyboard is not an Apple invention?
They have the highest product quality of any laptop manufacturer, period. But to say that all Apple products hold value well is simply not true. All quality products hold value well, and most of Apples products are quality.
I guarantee you that if Apple produced a trashy laptop it would have no resell value.
It's expected Intel-based Macs would lose value quickly considering how much better the M1 models were. This transition was bigger than when they moved from PowerPC to Intel.
One complicating factor in the case of the Intel Macs is that an architectural transition happened after they came out. So they will be able to run less and less new software over the next couple of years, and they lack most AI-enabling hardware acceleration.
That said, they did suffer from some self inflicted hardware limitations, as you hint. One reason I like the MBP is the return of the SD card slot.