If you sync your photos / videos with iCloud, you can download them as soon as you have a new iPhone, or to any MacBook / other computer.
If you run any backup of your photos / videos, you can restore them as soon as you have a new iPhone.
Without iCloud or backup, you could search on other devices it there are copies of your data.
If you have no synced the phone or if you have no backup at all, there is no way to get data from a iPhone if you have no access anymore.
