Sometimes useful. Like, if the setting is Japan, I expect sandals and tabi socks. North America, I expect moccasins. Much harder to justify in a Tarzan movie tho.
I agree that if the footwear is authentic to the clothing it is entirely acceptable ... and I myself had no problem with the knee-hi moccasins worn in the Tarzan Epic Adventures series as it was included from the start ... but the sandals Weissmuller wore in Tarzan and the Mermaids were not a good choice.
I noticed that on Apocalypto. I saw lots of sandals when they should have been barefooted.
I noticed that too on Apocalypto, and it annoyed me as well.
A lot of Mayans did, in fact, wear sandals. Probably not the same design.