I don't believe holding coins for 2-3 years long will maximize profits, it will exhibit a platonic state at some point and that would be a waste of time IMO.
A year of holding for me is the best way to go. However, going for the big guns like BTC and ETH then maybe yes 3 year might do.
the virtue of altcoin is more profitable in terms of quantity, so as much as any altcoin I buy for the long term, still no more than I buy bitcoin, I think if just buying altcoin without trading it in the short term, it would make the potential of active profit look very futile -sia because it is not used every day.