I'm not aware of any other country besides the US that has a blanket policy of requiring at least one interview in almost all cases.

That said, back in the 2000s I had to apply in person at the French embassy for a student visa, in in the 2010s I had to apply in person at a Chilean consulate for a special visa.

Many countries have outsourced the bulk of their processing to contractors like VFS or TLS these days. But also, our experience as Americans is not representative as we generally have fewer visas we need to bother obtaining, and face less scrutiny when doing so.

I'm not sure if the US interview requirement makes it "harder" to get a US visa - it may be that getting a US visa is just harder than getting another country's visa, which might still be true even if we didn't interview people. The big thing that makes getting non-immigrant visas to the US difficult for many people is that, unless shown otherwise, US immigration law assumes you are an immigrant.