Based on the understanding and knowledge of following up with the cryptocurrency for the past 6 month, my inference is that the cryptocurrency is highlt volatile.
Is it a good approach to stay invested for long term in the altcoin space?
Ask yourself "how much you are willing to risk for cryptocurrencies?" for sure you could realize something that might answer your question, because for me, it is worth the risk in the long run if you know what tokens you are holding, I mean if you knew in the first place that the tokens you are holding are tokens with great capability to be hold, then why not stay for a long term in the "Altcoin Space" you were saying.
But you are always free to quit or back out if you don't have the guts to stay any longer, always keep that in mind, you are the boss, you make decisions and sometimes it is a bad decision, but behind that, you always learned a lesson which is good.