Altcoins also depend on how you choose. Long-term investment is different from short-term investment. Many of the altcoins don't need long-term attention. You just invest and let it develop on its own. But after you invest in some altcoins, you should pay more attention to the market conditions. You may have to stop the loss in time for some reasons.
It would be wrong to assume that your altcoin is going to have development, although the devs will keep chirping about the same, don't forget that the dev is not your friend. While many projects will actually develop worthy projects most will not and you will likely pick up the useless ones if you randomly pick them.
For the most part in the bear market the coins will remain low but then during the bill market they will not go up. Sadly this happened to many traders being stuck with low priced coins. You can easily go with the top five, but beyond that commenting is difficult.