Mac OS has supported a similar system since the classic era – for example, https://en.wikipedia.org/wiki/Compose_key leads with Compose + ~ + n = ñ, which is Option + ~ + n on Mac OS.

https://forlang.wsu.edu/help-pages/help-pages-keyboards-os-x...

The newer system is simply holding down keys to see accented variants which feels very natural on touchscreen devices but is slower than keyboard shortcuts if you know them.