Where did you hear that surrogacy is banned in most places outside the USA? That's just not true, and I suspect you've been indoctrinated with more US-exceptionalism. Surrogacy is not banned in the UK, Australia, NZ, much of Europe, Iran, much of Asia, etc.
It's "legal" at first glance but it's effectively banned in most cases. No monetary compensation, only direct relatives, only traditional pregnancy, etc.
It's outright banned (commercial) in most of EU. In most countries it was left unregulated for a long time but most of them are choosing to ban all commercial forms of it. Besides US, most major countries have banned it.
Now many people do ignore these laws and most governments do little to enforce them unless they make the news for some reason. Banning commercial forms of it just ensures abuse and issues go unreported. It's the paternalistic part of feminism that's been leading the charge for modern bans, with both liberal and conservative roots.
Surrogacy is illegal in Spain, Germany, France, Italy, Switzerland, Austria, Norway, Finland, and Turkey. Also banned in China, some states in the US and Québec.
Thats a pretty hefty chunk of the worlds population.
A lot of other countries also have a limbo status where there is either no clear law making it illegal but put so many hurdles up that its impractical.
Some countries, like Italy, also make it illegal for Italian citizens to go abroad to a country where it is legal and then do it there.
