The video has a short section on productivity (i.e. rendering or compiling). That part is probably the most relevant for most people. Check the chapter view in YouTube to jump directly to it.
I think a 2x performance improvement is plausible when comparing non-soldered ram to the Apple silicon, which goes even further and has the memory on the die itself. If, of course, ram is the limiting factor.
The advantages of upgradable, expandable ram are obvious. But let’s face it: most people don’t need and even less use that capability.