I don't think transhumanism can make life more meaningful for someone whose life was not meaningful before. They're not related concepts except as transhumanism pertains to extending one's lifespan, which could give someone already living a meaningful life more time to accomplish the things that make their life feel worthwhile.

Transhumanism as a means of extending the lifespan of someone who lives only for themself seems like a trivial idea. If it cost nothing, then why not, but if it's at the expense of others, then it seems foolish to me.

Yes, every few months we have an article about how senescence isn't natural or unavoidable, but having said that, OP makes good points; money and things and time spent watching TV/playing video games don't add up to a meaningful life for most people, regardless of how long they live (or the realm, physical or digital, in which they exist).