Toyota has massive scale, is very successful, and is japanese, and thus has extreme inertia on change, even in software where such things 'should' be faster. Their existing infotainment has been considered fine and functional for years, and Toyota likely didn't start seriously considering it till consumers were already demanding it.
What's the reasoning behind this? Apple itself tends to be late in supporting a lot of things, but when they do it's more polished then competitors.