If BTC is high, and alts like Ledu, eth, litecoin, vechain are low or affordable as u pointed out, then you're missing the whole point of cryptocurrency.
What does it have to do with it, there are trading cycles in the cryptocurrency market. Now Bitcoin is very popular and it has given investors good profits, who bought at 4000 dollars. But there will be a time when Altcoins will be traded with great profit, their dominance will increase.