There is theory that the longer something lives the longer it have chance to survive. So BTC is best safe ofption to invest and hold crypto.
Same time you have alts and what then ? You don't really don't know.
Look how other projects where hyped like Dash while ago now is quite becouse as live shows no one cares bt most people are looking at BTC price if its rising then they buy crypto or not.
ETH have some ground but same time changes that will be sooner or later wil divide that comunity so you won't know later what to hold.
You have free will you can gamble and win a lot or not gamble and keep your possetion.
In my portfolio BTC is like 95% of savings