Agree, for most 30 knots average wind is the upper limit where it is still fun and the typical kitesizes work.
Meaning 7 m2 for hardcore kiteloopers (smaller kites drop way too fast), and 5 m2 kites for waveriders, average weights.
Of course you can kite in 40 knots or more, but for the majority 30 knots is the max where enjoyable and typical gear fits.
You can get smaller kites 3 and 4 m2 (LEI) but not from that many brands.
Now where hydrofoiling is big, there are many small kites 2 and 3 and 4 m2 yes, both foil and LEI kites, but some are made for hydrofoiling and not all suited for massive load.