Buying Bitcoin at an all time high strikes me as a experiment in bag holding. There are something like 8000 cryptocurrencies out there - more than stocks on the New York Stock Exchange. Unlimited quantities of numbers on a computer system that can be infinitely recreated by anyone at any time. No wonder bankers are tripping over themselves to offer access to people - try to get your piece of the free money tree before it inevitably collapses on itself.
Buying Google and Amazon and Apple at an all time high worked out well for me.
You're right, there are lots of stocks, and cryptocurrencies out there, also lots of bond and debt instruments.
There are apparently 9600 mutual funds in the US (quick google search)
The question is which of the thousands are worth buying.
Just because some, or many of the available options aren't good investments, doesn't mean the whole asset class is bad.
The Crypto boom is just like the Tech Boom, where they were getting massive IPO's for all sorts of silly ideas. Most of those tech companies were dumb, and not worth it.
Today there are lots of ICO's, most of them are dumb, and not worth it.
However there remains the opportunity that there will be value.
Additionally regarding digital assets. Digital assets are a thing now.
Do you realize that Fortnite had almost 2 billion dollars in revenue last year?
Do you know what the users got for those billions? A different appearance in the game, and the ability to give their character different dance moves.
You can play the exact same game, without paying a penny.