There is no doubt that the future of altcoins is bright but not all altcoins. There are some good projects out there which will pay good reap to the coin holder. So, it is necessary to do deep analysis and also you have to pass some time with the project. You have to stay with a good project by staying with there social media or other platforms where they update daily, you could see the seriousness of the team and upcoming future of it. It is better to follow up a project for a few weeks by staying with the team of the project. You can ask them critical answer too.
After all, holding altcoins is good but only the best one which has value.
Thanks.