easyJet have coexisted on the Liverpool route for around 11 years. I don't sense that they actively force others off the routes where there's direct competition.
The questions should be around what government can do to increase competition and encourage the numbers of routes and destinations. See Jersey as an example - rather than handing out bungs or route licenses or doing closed skies.
Whilst the IOM relies on the TT, farming, fishing and retail there are always going to be issues 😁
Only joking with the last bit