Not if they were the two people catching a bus that made running the bus every 15 mins rather than every 30mins viable, so now 40 people stopped using transit and 20 of them drive and take a park each. Then this slowed two other bus routes, and so on.

Induced demand and congestion are complex. A taxi is probably better than a car, but neither cars or taxis have enough capacity to viably challenge congestion. You need mass transit that runs frequently and isn't stuck behind cars.