RCV simulates a "runoff" but in a single decisive election so that voters need to turnout only once to vote. In a single-seat election, candidates are incentivized to campaign toward a majority of voters and win with broad popular support. In a multi-seat race (for 2 or more seats), RCV ensures winning candidates are elected in proportion to the share of voters who vote for them thus ensuring fairer representation.
Regarding the concern that RCV does not produce majority winners, the winner (in a single-seat race) is always the candidate with the majority of continuing ballots in the final round, even if sometimes that is not a majority of the total ballots cast. Some ballots may be exhausted before the final round of counting if some voters choose not to rank enough candidates, but that will generally still represent more voters than likely vote in low turnout runoff elections held today. Voters are therefore encouraged to rank as many preferences as they have.