All in? HELL NO, nobody should go all in, regardless of age. Taking higher risks when younger--that's all well and good. But going all-in on anything crypto is a recipe for bankruptcy. I wouldn't even allocate 20% to crypto. You'd have to be crazy to go even half-in, and I say that as a person who likes bitcoin. A lot. It's just way too risky.
Investing in bitcoin is a good idea, it is an investment that will surely help anybody, or anyone who wants to enter business but if you say business it involves risks that is normal for businesses. So i would say that young people must invest really, but to go all in is each of ones opinion because it's each one's money who is at risk so it's each one's opinion.