In the grand scheme for sure it's still early, with plenty of sats to be redistributed, sats to be lost, and markets to open up to, and you can ride that network growth. If they think its too late, then allocate according to your reasoning, if that's 0, 1%, 5% whatever amount you think is the right exposure for you to go through as a long-term hold
If you're thinking it too late, it probably is based on what you hope Bitcoin would do for you, I've seen it so many times from friends coming into Bitcoin with the mindset that its a trade and a moonshot trade at that, sure there's plenty of upside, but if your goal is to multiple x in a short space of time you're going to be disappointed with bitcoin and want to take leveraged bets either through alts or derivatives and end up rekking yourself.
I've never been good at convincing people why Bitcoin, maybe my experiences have tainted me.
ahhhh, remembering my days when i explained bitcoin to my girlfriend. Its a horrible times , hopes she doesn't read this HAHAHA..
Just explain him the truth, yes BTC now is expensive unlike 5 yrs ago but think this " if bitcoin rise considerably in the last years, then its okay to take risk in the upcoming years and it might or maybe BTC market price will go to 100k per, thats insane".