Google is working on a 'fix' that is resulting in iPhone owners getting free unlimited storage in Photos online for full quality photos using its new default HEIC file format. HEIC is a newer compression technology than JPEG and the result is that iPhone owners are currently getting a free ride on full quality photo storage while Android, and even new Pixel 4 owners, are capped a 15 GB of full quality photo storage.
https://www.notebookcheck.net/Google-to-put-kybosh-on-HEIC-loophole-giving-iPhone-users-unlimited-full-quality-photo-storage.439917.0.html