Those of us outside the US would still see some usages; "encyclopædea" in particular isn't uncommon.
British usage usually preserves the "a" and "o" in those diphthongs.
Oe is also used in the same way I suppose, oestrogen for example comes from οιστρογόνο so in this case oe is transliterating omicron iota.
Some more here: https://en.wikipedia.org/wiki/English_words_of_Greek_origin#...
I was actually a bit disappointed that she doesn't mention all this in the article, "ae" is not aesthetical (another greek-derived word) ffs, it very often maintains the historical orthography of the word which I feel is very important.
Classical Latin just wrote out AE (and it was always in capitals because minuscule hadn't been invented yet). In the middle ages, after sound changes resulted in AE being pronounced just like E, they switched to ę (called e caudata, the little tail at the bottom being called a cauda). In the early modern era, scribal abbreviations fell out of fashion and they went back to writing the a... but they ligatured it with the e as æ in order to make it clear it was a single sound.
εν-κύκλος (in circle) --> εγκύκλιος παιδεία (education)
The core, generalized education one should have.
Words like paedagogic etc are also spelled like this in english (uk) because the language maintains the historic spelling