Am I missing some obvious way to change this lightbulb?
After an hour of searching google

Home Depot



Looks like your light

Taking the description from the Home Depot page, I found this PDF for installation instructions

PDF

Looking at the PDF and the photos, it looks like there is a white trim ring around the glass. Instead of prying from the trim that touches the ceiling, see if theres another lip closer to the glass where it flattens out. It is probably held in via compression.