Exactly, if the body ages in 90 years to only 30, all organs should as well, including the brain.

This means that age-related diseases like heart problems, alzheimer, etc, should not occur (except where they already occur in young people).

> all organs should as well, including the brain

In theory - this assumes that the drug has an equal effect across the entire system and that all organs will age at the same rate. It may, for whatever reason, not be the case and things will age at different rates.

How about senses? Hearing loss can be non-repairable. Likewise with vision / macular degeneration that may not be fixed with this. How about taste?

It’s a nice idea to think that everything will just stay the level of a 30 year old over the period of 100+ years is, in my opinion, wishful thinking. It will still age, just in different and unexpected ways.

I totally agree with you. Tear and wear on the body will continue as will the clogging of the arteries.

Not all aging is cellular indeed.