Isn’t one of the primary arguments for condoms is that folks in third world countries find them useful?
If the use patterns show that even educated first world people get them consistantly wrong, that’s a design flaw. Especially given the claimed market for them.
This is one thing the Billings method does well - cervical mucus is actually easier to understand.
It’s not a design flaw. It’s a device with known limitations. You’re blaming the car for college graduates not wearing seatbelts. Maybe our 3rd world folks by not having grown up in a world where these things are second nature actually bother to follow the instructions better.