Why is my iCloud storage still full even after deleting photos and videos?

This is ridiculous I’ve deleted more than 20 GB of photos and videos from my phone and it doesn’t even give me 2 GB of space, how many things of my 600 GB media on iCloud do I have to delete before it deletes the ones on my phone? Who has time for this mess? I would back up everything and never use iCloud again if it didn’t take hours and days. I would reset to factory default to remove system data too but I don’t want to mess with my banking apps right now or my authentication apps

[Re-Titled by Moderator]