Hodling can give you good profit but not in all cases, meaning not all the coin you hodl. Before hodling, you can check if the community is active and this is important. If the coin is in cmc, you can easily check there to know the direction that it is and how it can grow in the future. You have to study a coin before investing in it. I have invested blindly too and seeing price slump painfully.
It's good you acknowledged you've also invested blindly in the past and learnt from your mistakes. Some people just jump into buying a coin when there is little hype around it, or when it's called by a pump group especially on telegram. I asked one of my friends why he bought a coin two weeks ago, his reply sounded like its coming from a newbie. He said he is buying because the coin is so cheap, when I checked, the total supply was extremely huge, the team hasn't been active and there is zero development, the daily trading volume is below 200$. I wonder when people will stop being lazy to do proper research before buying any coin, especially holding for long term.
I agree with your opinion, a lot of people are lazy to do proper research before buying any altcoin, even though the key to successful trading is to research an altcoin first before buying it, is it true that the altcoin we choose has great potential, if yes we take, if not we don't buy it. It is very difficult to research, but if we are not careful like that instead of profits instead of losses that we will get, and only regret will come.