According to him, his fear is that if he sells it during the next bull run, he will be taxed, and he doesn't want that.
It's silly if the reason he doesn't want to sell his Bitcoin is because he doesn't want to be taxed. He would sell it and receive fiat, he's already being taxed heavily in fiat so what difference does it make?
A question arises: Would taxes still be applicable if a time comes when exchanging bitcoin for fiat is no longer necessary?
In a time when we wouldn't need to exchange Bitcoin for fiat means Bitcoin has now been globally acceptable as a means of payment. If you're being paid with Bitcoin you'll pay income taxes.
If you buy stuff with Bitcoin you'll pay the VAT and other taxes just as it is with fiat money.
But all these depend on the country you're in.