It's like asking if it's better to invest in old stocks or new stocks — it'll totally depend on which stock(or token, in this case)!

The only advantage of newer tokens is that there's a good chance that it'll have a not-so-shitty chart; whereas most old tokens will likely have a shitty chart. That doesn't mean old tokens can't pump though — take a look at MakerDAO and the like; they haven't reached ATHs, but the bounce looks really good.