iCloud storage not freeing up after deleting photos

All the work with your iCloud files has to take place inside of your iCloud account. In order to delete files, iCloud has to be able to move them around. If your iCloud storage has almost no room left, then it may not be able to clear any space. (Your iPhone needs to have at least 10% of its storage free for the same reason.)

You could spend a buck for one month and get enough room in iCloud the get some results.

Apple gives each Apple Account 5GB of space in iCloud at not charge. That's not enough space for most of us. So we buy more space in iCloud and don't have to worry about deleting memories, apps, files, etc. It costs a measly $1 per month to go from 5GB to 50GB. $12 a year or about the cost of two drinks at Starbucks.

See how to upgrade your iCloud Storage here --> Buy iCloud+ or upgrade your current storage plan - Apple Support

I realize I didn't really answer your question, but for a very small investment, you just don't have to worry about having to constantly manage your storage in iCloud.