How reasonable long-term investments in altcoins are can only be said in relation to a specific altcoin. Some live on for a couple of months on the strength, and are suitable exclusively for short-term trading, on which you can make great money if you have time, or lose everything. It all depends on luck. And they are in the majority. But there are also those in which I invest now, and I expect growth by the summer. It all depends on the development of the project.
Sometimes it doesn't just depend on the development, it also depends on how famous the project or coin becomes, because a few years ago I was in a very good privacy project, under which it had an excellent development and everything was going very well until it was They got involved with the investors and apart they did not want to list the currency in a level 1A exchange, from that moment the investors extracted their investment by lowering the price of their currency from 20USD to less than 1USD, this was something disastrous, and it never recovered, nor when BTC had its last ATH. This consideration should be taken into account, especially for new projects that come out.