Small momentary switches cost pennies and laptops usually have about a
hundred of them fitted, of various kinds. (Power on/off/suspend;
volume up/down; keyboard keys; maybe others.) So, fitting laptops with
momentary switches is definitely acceptable to manufacturers.
I'm guessing you don't work in a company that designs or builds laptops :-) b/c they agonize over parts like this. I ran into one situation where the ODM removed a single pulldown to save cost. One little almost-too-small-to-see part which cost a fraction of a cent. But a laptop BOM is a consequence of thousands of decisions of this type.
Nope, the switch is definitely a non-starter, esp. given that there are solutions that don't require it.
It's not just the part. A single simple part like that has all kinds of follow-on effects that are not obvious unless you've been at a company which designs and builds consumer electronics.