The answer is that it doesn't have to be but it's simpler that way.
A transcript has to be written for a YouTube video essay, and there's not really a major reason you couldn't turn your transcript and footage into an article with a series of embedded gifs or graphics. It's just much simpler for creators to dedicate their time to one medium and not worry about losses in translation or similar issues.
part of the reason why thats required is because sodimm format has hits its frequency limit (that is, its getting much harder to get it at higher frequencies without stability problems). soldering lpddr ram gets passed this problem but makes it hard to repair for obvious reasons. Dell has allowed for its up and coming CAMM standard of ram to be used without royalties, but it hasnt been implemented often yet.
for iGPU performance, ram frequency is very important for overall gpu performance because memory bandwith is usually the #1 bottleneck for gpu performance.