I'm not sure how strong a network effect other than in a local area. I'd be pretty sure that (in normal times) their primary market isn't business travelers flitting from SF to NYC to London but residents of $CITY using Uber Pool for commuting or Uber to go out with friends on a night out to a bar.

Contrary to that, local profitable markets like Manhattan have had significant entrants eat away at Uber’s market share with companies like Juno scooping up the best customers and drivers. The same thing happened in many cities in the early 20th century before streetcar operators managed to get jitney cabs (the unlicensed pool taxis of their day) banned because too many teens would borrow the family car after school and drive in front of streetcars on profitable lines and scoop riders for nickels instead of dimes.

Uber and Lyft have a de facto duopoly amongst those hopping off planes because it’s hard to know that there are any other local options available.

And for that matter, I often take a cab from the airport because it's not my money and I can't be bothered to mess around. Uber and Lyft are often more trouble than they're worth.

But if there's a local alternative known to be better for going out with their friends, you can be sure that a person used to going out regularly with their friends will know what it is.

Perhaps negative brand loyalty, to be honest.