Uber will continue to grow in profatbility. As the platform matures and continues to grow in revenue, the overhead development cost will actually decline, not just as a percentage but as an absolute number as well.
Furthermore, Lyft being borderline bankrupt helps Uber take more advantage of the most profitable and largest market.
Mature in a sense that Uber has invested billions in operations to get deals with cities & airports, developer legal expertise globally, and has technology that allows them to operate globally.
Saying Uber is "just an app" isn't a strong argument. It overlooks the marketplace dynamics that in themselves are a huge moat. You can also say "Instagram" is just an app.. But good luck trying to recreate that level of success.
It's similar to Tesla in this regard--a decade of losses from 2010-2020 and then -boom--huge cashflow once the infrastructure outlay and customer base acquisition pays off. 'Smart money' was right all along to keep buying the dips. Uber is a play on not only on transportation, but also Ai, logistics, delivery, etc. It's like Amazon in this regard.
Furthermore, Lyft being borderline bankrupt helps Uber take more advantage of the most profitable and largest market.