The Raspberry PI wallet vote is dominated by customers that have no reason to toy with replacing RAM chips. They want consistent quality from reputable sellers, and they appreciate that a door has been closed to Asian board rework houses, filling the supply chain with unqualified parts.
Honestly, that's what I want from Raspberry PI as well. I know the RAM is soldered when I buy it. I have nothing to complain about. When I want something less carefully controlled, cheaper and more flexible, there are ample choices there as well. Raspberry PI need not compromise their standards for that purpose.
The last few years, my Raspberry PI use case is a high-end ADS-B feeder: mast-head pre-amp and filtering, low loss coax, high gain antenna, 14-bit SDR, properly powered and grounded, running in non-room-temperature conditions, 24x7x365. The software is qualified, running on qualified hardware, and it all works flawlessly: every update works perfect, every power-outage is recovered from, etc. That's what I want from Raspberry PI and I'm glad they are there, providing a high quality, reliable platform that others can target without troubles and issues.