I had a similar experience, having used EarSonics IEMs and own a pair of custom Noble Audio ones too, alongside Hifiman open headphones with a nice DAC/amp. The sound doens't compete at the same level, but it's so convenient, feels way more comfortable than any of the above, and quality is adequate for me to enjoy the music I listen to, so in practice I've barely touched all the other cool audio gear I have since I bought the Airpods Pro.