> gluing everything together enables more compact, durable designs

Maybe a tiiiiiiiny bit more compact, but definitely not more durable. Frame.work can apparently produce easily serviceable, rather thin designs of laptops that are even modular (www.youtube.com/watch?v=0rkTgPt3M4k). This is way thinner than my 2008 era HP and thinner than my 2021 era Lenovo.

As far as phones go, the PCBs are a tiny part of the phone (The cpu, ram, storage combined are less than 1/2 of the phone surface area and probably less than 1/4 of the volume) so gluing them together doesn't even get you much. You might get a _small_ bit by soldering in the battery in the sense that you then don't need a "box" for the removable battery, but that is a small amount of space compared to the battery itself.