Is 128gb so much? My last workstation (not a laptop) had a 5950x and 128gb of DDR4 and that RAM is like 4 years old now.
I am not saying you will have it in an ultrabook form factor, but I had 32gb of ram in sandy bridge laptop (intel core i7 2700 ?) and 64 not that much later. That was like 10+ years ago. Those were desktop replacement and thicker style laptops, but not exactly unreasonable equipment.
I use a lenovo laptop, a t15g2 because of 4x dimm slots that let me fit 128gb of ram, and yes, I tend to use that even under linux. I tend to do work and personal business across this device, which includes full separate firefox profiles for each, usually 4-5, and it's not uncommon to see it or chrome/chromium actually using 60-70gb, not just reserved, of ram alone each connected to gapps, teams/orfice365, whatever needed for work.
Throw in almost always using a windoze vm for windoze things for another 8gb, at times other vm's using 4-8gb doing various things for testing, libreoffice with 20 complex spreadsheets, steam games, normal use really, all adds up to a lot of at minimum reserved memory far exceeding physical, at times things ballooning within that, and thus at times getting cranky to still oom occasionally.
I rather wonder who actually uses boxes with only 8gb of ram some still ship with.
I do stuff that uses all my RAM. New workstation has 192GB already had builds that pushed it to 180gb used. I am not alone.
I am not saying everyone needs that much, just that the bar for what warrants a dedicated server rack keeps going up and 128gb in a thick laptop seems practical.
Windows 10 (and 11) works fine with 8 GB. You may be using applications that need more. The minimum requirement for 64-bit Windows 10 is only 2 GB, and even 4 GB can be workable depending on the application.
I am not saying you will have it in an ultrabook form factor, but I had 32gb of ram in sandy bridge laptop (intel core i7 2700 ?) and 64 not that much later. That was like 10+ years ago. Those were desktop replacement and thicker style laptops, but not exactly unreasonable equipment.