It is a good decision if you invest 60% of your savings in bitcoin, in other words you have 100% of your savings and of course you have managed your needs well so that you have savings and risk funds or emergency funds for your needs in the next few months. . 40% of savings if you feel enough with it to cover unexpected budgets beyond the budget needs that you have made before.
Maybe I'm trying to understand that 60% is from savings not from the income you have, so I totally agree about investing 60% of savings.

I am not an expert on this but if you look at history the cycles will always repeat, you will not lose 100% of your money in bitcoin but it will be lost if you keep it in altcoins.
If you talk about going up or down again for bitcoin, I don't think you need to be afraid because you can use the DCA strategy to reduce frustration when it goes down and for sure bitcoin will return to its highest price and you just need to be patient.