As a data point: I got a 14" MacBook Pro with a 512 GB SSD the first day it was available in 2021, and I've used it daily since then.
According to the SMART data ("smartctl -x /dev/disk0"), the SSD "percentage used" is 7%, with ~200 TBW. At this rate, the laptop will probably outlive me.
NAND is still the same wearable part that regular X64 laptops have, Apple doesn't use some magic industrial grade parts but same dies that Samsung, Micron and SK ship to X64 OEMS, and those are replaceable for a reason, because they eventually fail.
The MacBook neo is for students, grandparents, travel, etc.
Hell, even if it dies after 6 years it was still a better experience than using a $500-600 windows PC and the cost comes out to ~$8/month spread over 6 years.
Do you think SSD drives are replaceable for no reason? Just because M1 mac aren't failing left and right doesn't mean their NAND won't fail.
Even though I like the NEO, I can't in good faith buy a machine with soldered wearable parts. That's like buying a car with soldered brake pads because "in 6 years average users don't feel like they need changing".
I still had laptops on my hands from 20 years ago that work fine simply because you can swap their drives with fresh ones. How many M1 mac will still be functional in 20 years?
(But it's encrypted, so you'd better have backups because you can't read it off the chips.)
Probably quite a few, MacBooks have had soldered SSD's for over 10 years now. My 2018 McBook Pro still has a perfectly functioning SSD. I still see people using 2015 and older MacBooks all the time. There is no widespread SSD failure issue after 10+ years of Apple soldering the SSD's.
For most people the SSD's are lasting longer than the useful life of the device.