Looks like I can mark this one as Solved ✅
Quick reminder for anyone else landing on this thread: we have a full guide on the site titled How to Delete All Photos from iPhone that covers just about everything mentioned here, and then some. Definitely worth a quick read if you're planning to clear out your library.
If I had to quickly summarize the methods from our guide, it’d go something like this:
You can remove everything straight from the Photos app: tap Select, start swiping upward to highlight older photos, and keep going until everything’s selected (or tap the top of the screen to instantly jump to the top). Then tap the trash icon and confirm.
If you’re using iCloud Photos, you can also go into Settings > Apple ID > iCloud > Photos and toggle off Sync this iPhone. Choose Remove from iPhone, and your local copies will vanish while iCloud keeps the originals online.
And for anyone with a Mac, there’s an even easier route: just plug in your iPhone, open the Image Capture app, press Command + A to select everything, and hit the trash icon. It’s by far the fastest way to delete the entire camera roll in one shot.
Also, don’t forget the Recently Deleted folder. To fully wipe them from your iPhone and free up space, you’ll need to open Recently Deleted, tap Select, then choose Delete All. That’s what actually clears them out for good.