Companies like eBay have a global footprint and send/receive money in dozens of countries. eBay has apps for all devices and a website.
Uber has 3x the headcount as eBay.
Uber has 3x the headcount as eBay.
The eBay business requires no boots on the ground, Uber Eats does because they have to equip riders. And eBay has almost no market-specific laws/regulations which change every couple of months to worry about.
I think eBay doesn't process payments, that is outsourced to PayPal.
It looks like eBay is in about 25 markets, Uber is available in 85 countries.
Serious question: Why does eBay have so many employees? It's just a search engine for a user generated product catalog where users can place bids on the items. My guess is that most Uber employees aren't high-paid developers, it is more likely that they are in support roles.
Uber has to market themselves which needs local expertise, if nothing else to liaise with a local PR firm. Then they need local legal expertise to actually operate in the country (eBay transactions happen online, and the transport agency hired by the seller figures out how to get the package to its destination). Uber then has to have maps for every country it operates in, as well as change their standards to match local expectations.