But even then, an example I would use the Kirkby to Liverpool on the 20/21. Duplicated the train line for 90% of the journey but both run happily alongside eachother. Passengers choose which is best for them. The bus carries people locally and the train carries longer distance despite running alongside eachother. Anyone going to/from Kirkby Town Centre must use the bus and if you told these people you have to get a bus to the train station, catch the train to Kirkby then get the bus into the city centre, they would just come off public transport.
Similar could be said for the Stagecoach 216 vs Metrolink. Both carry passengers and are very busy as people base it off which mode is closest to their origin and destination and the price. If every mode was made the same price, that elimates 1 issue but if the tram is cut and people are going to Cornbrook, they will likely switch to using their car. If the bus is cut, people won't walk so far to the tram stop so then they switch to their car as the walk to the tram stop is too far.
Such ideas to completely cut a mode of transport are 99% bonkers. They would be a step back for getting people onto public transport and would lead to huge congestion issues with people getting back into their cars because of the inconvenience of changing modes so many times to make a journey. The only exception is Blackpool where is makes more sense as south of Cleveleys, there are only a few areas which the bus stops but the tram doesn't, in some cases, other bus stops are available close by though for the 3/4.