> it's too easy for any local city to have a dominant "Uber for our city" which isn't Uber

I disagree. By virtue of being in the city, and only in the city, it would be too small to withstand pressure from local interests for long, and would end up like the local taxi monopolies. This will be especially true in countries "with lower GDP per capita".

Uber's international nature with its HQ in a country where corruption is relatively low, clearly enormous political and financial connections, track record in neighbouring countries or cities with clear and visible benefits to the customers (aka electorate), and willingness to fight (which is public knowledge, thus becoming signalling) allow it to scare off such pressure. Uber has more to fear from Apple than from Paris' UberX clones.