Of course it is logical to do take a decisive decision as it regards to ones investment because investment is something we can not predict the outcome of how it would be but we can gain sight about it based on speculations and assumptions. So being sceptical of old coins doing well or not is part of the calculations to avoid being at loss.
Just as you have said that many got good rewards from investing in old coin while some do not. I must say this that not everyone is fortunate to have that experience. Some investors are smart enough to get into projets at their earliest stage and it worked for them while some do that later and miss the opportunity to take in big profit. It all depends on the he investors. In all, trading is risky and that is why you are advised to apply caution and trade with care.
Choosing old or new coins depends on our ability to do research and make predictions. because new coins can also generate bigger profits if we can choose a good coin or project, even though most investors are more confident if they invest in old coins. That's because they don't dare to take bigger risks.
If you really want a challenge, of course, by investing in a new coin, because you can be sure you will get a very good profit because it is usually always a cheaper price and a bigger bonus, but if you analyze it well, it will be the opposite, so that it can suffer losses because it is not valuable.
But with the old coins that have been included in the best ranking, they can be sure they can survive until now because of the trust of investors in them, so we will not experience enormous losses.
All returned to those who have funds where they will are located.