DYOR, weigh the risks and make a balanced portfolio that consists of multiple things, not only BTC and alts, but also maybe stocks and precious metals.
I guess OP doesn't experience how risky the cryptocurrency is without taking too much precaution when investing a single cryptocurrency. Either 100% bitcoin or altcoin portfolio none of them would matter if one will have a recession you can't do anything for your investment if that's going to happen. Although bitcoin might give you a chance but it would still be better if you do hold more crypto in your portfolio so you can diversify if things go sideways.
Bitcoin holders do not need altcoin to earn big amounts. They are just required to understand bitcoin better and work with it well. If I am not wrong, then it was bitcoin that produced millionaires first and only this coin can return huge profits. Altcoins depend on bitcoin so an altcoin holder should invest in the king of crypto currencies too, if not done already. Above all, trusting your asset is a must.