[returnInfinity]

Even if they lower costs to 0, it means nothing

Topline growth matters more than costs.

Mathematically - There is no limit to topline growth But cost cutting has a ceiling, which is the current costs.

You can only make(save) so much money with cost cutting

Topline growth is upper bound by total energy in the universe though.

[Legend2440]

Topline growth is more realistically bounded by the number of people willing to take an Uber at a given price. You can't expand forever.