Earlier quoted context omitted.
There was a free tier of photos and videos under a certain resolution which didn't count towards your storage which they're removing.
I was under the impression that was only for Pixel phone owners - I suppose I was mistaken! Although low resolution image uploads doesn't seem very useful for most people. The point of cloud storage is peace of mind to keep your data safe... and to me that implies the original photos not reduced resolution photos.
They are still very high resolution. They're just not the original 50 MB file. It worked perfectly well for the overwhelming majority of people.
Pixel offered unlimited storage even for uncompressed photos, but that option was also discontinued a few years ago.