It has its demerits and merits, one, there's no certainty that any invested amount will yield return on investment in the foreseeable future. But if one has to invest, I'd suggest investing in a number of coins instead of 1 or 2 coins.
I agree with your suggestion, by investing in several coins it is more promising than just one coin, because we have other choices if the assets we have are in a bad position, so we can see the development of other coins that we have