Bitcoin and ethereum is not a new coin so i believe in old coins it can make profit that new coins that is very good at first and in a long run turn into a scam and abandoned by its developer.
Yeah you are right, old coins are the best to invest into in other to have peace of mind, a lot of new coins has destroy and frustrated a lot of people and some of all this new coins are scam and should be avoided, a friend of mine invested into one new coins that came out those days and he used a very huge amount of money to invest into it and the coin started growing so he sold all his coins quick and made good amount of profit before the coin fell in value and price he was luck with that invested and he was very happy so he decided to invest again and he did but he lost all his money into it, what am I saying here investing on new coins is very risky and should be avoided, a lot of people choose to invest in new coins thinking they will make good money from it but reverse is the case, so I will advise newbies to focus on old coins.
A lot of people thinks old coins like Bitcoin won't grow again so they choose to invest in new coins with the believe that they will one day grow and become like Bitcoin, if you need to invest in a coin and have peace of mind I think you should invest into Bitcoin, those investing in new coins are always panicking and thinking about there money, they don't have peace of mind that that's because investing on new coins are very risky, there's high scam rate now in new coins.
Bitcoin has not even reached half of it's growth level so I don't know why some people believe Bitcoin won't grow more than it is now people that were having this believe before are now regretting, so is best will stick to old coins like Bitcoin.