What happens if rapid test is positive?
You've partially flown the flight all the way from US or Europe etc, so any refunds or vouchers will be negligible value.
Qatar bans entry of foreigners (or you might have a nationality that requires Qatar visa even under normal terms, so you can't enter Qatar)
Likely you can't be put on a flight back to where you boarded because firstly, you tested positive, but also, to be allowed entry back in your origin it will likely require a new pcr test, forms, approvals, whatever onerous requirements for entry are on that end.
So, what EXACTLY happens to someone who tests positive. They're stuck at Doha airport for two weeks?