Raspberry Pi is intentionally blocking RAM capacity upgrades

the measure is primarily intended to prevent third parties from buying lower-capacity boards, replacing their RAM with cheaper parts of uncertain origin and then reselling the modified hardware as a higher-capacity model. The company argues that such modified boards have not undergone its validation process and could subsequently generate support requests if unstable memory is blamed on the company.

The solution to this decidedly rare problem is authorized resellers, not an arbitrary block on a very technically demanding upgrade.

That’s assuming this is the actual problem though. If the problem is actually “We want to make more money by charging extra for ‘enthusiast models’” then this is the correct tactic to ensure that you aren’t undercut by cheap labor.