Kevin719 straight from the source and it is not a new thing
https://blog.google/products/photos/storage-changes/
You'll have to make sure your uploaded photos are not in original quality, i.e. less or equivalent to 16Mpixel, FullHD videos up to certain size to not count towards total allowed storage. Make no mistake, all media gets scanned so Google can present you with suggestion for deletion of "imperfect" media (I bet AI is hard at work there).
@yore although your statement about overall privacy using GrapheneOS with sandboxed Google Play may be true, this advance as opposed to stock is marginal at best. Many new users (and they don't seem to be shy to voice their opinion regarding this on here) may wish to skirt using it altogether to maximize privacy benefits GrapheneOS brings.