Businesses might want to be settled in the currency of their home country for ease of accounting/taxes and not be subjected to high volatility
So they choose bitcoin?
The whole point is that PayPal shields the business from the volatility risk. Buyer buys in Bitcoin, seller receives local fiat currency.
I think the point here is probably that Paypal is noticing that an increasing amount of consumers have crypto and would like to pay with them, so they offer this possibility.
Bitcoin is just another currency, and indeed most businesses don't want to hold them because they need to hold their local fiat. That doesn't mean consumers don't want to use Bitcoin tho.