Single fares with distance-based pricing will not penalise passengers who need to change buses.
If we want to be serious about encouraging people to give up driving, we need to have the SINGLE FARE lower than the marginal cost of driving, such that people will only drive when public transport can't reasonably serve the places they want to go.
In Hong Kong, most bus fares are cheaper than the fuel cost of a car alone (it is comparable to the fuel cost of a motorcycle), combined with the difficulty of parking, public transport achieves more than 80% of the market share there without a strict quota on car ownership (unlike Singapore). Bus fares are regulated by distance, but not strictly priced according to it. Some bus companies couldn't get regulatory approval to sell monthly tickets because it would unnecessarily penalise those passengers who don't travel long haul often, to the extent that they would cross subsidize long distance commuters.