I agree with you, old coins that already have products are safer to invest than new coins, because we can already see the progress of old coins that already have products and of course old coins will be more popular than new coins, so the price will definitely continue increase and give us profit.
Not all old coins become popular in the cryptocurrency market, it still really depends on the team's concern in developing their coins and products for everyone, because the popularity of a coin happens when the users become more and more, so you should know about this too and always analyze all the coins so you can make a choice on any coin, because hitting the flat in the form of the same rating is not very good.