Warren Buffet said "Diversification is a protection against ignorance," I'm all on on bitcoin!
Bitcoin is the best performing asset in the past 10 years. There's no point in diversifying any further when you understand and believe in the future of bitcoin. Big gains still to come!
You weren't invested in bitcoin for 10 years, so using that as a comparison is meaningless. In fact, I'm willing to bet there are loads of better performing assets by the time you got involved, and there will be better performing assets from this point on as well. Blindly assuming that bitcoin goes up no matter what forever is exactly why there are people currently sitting on 50% losses when they were buying at $64,000.