Instagram changes their code regularly to prevent mass scraping and downloading from their platform. My developer created a script to scrape images from accounts that didn't require accounts to be logged in.... it worked for unlimited downloading for approx 96 hours, and stopped working. Paid him to update it, worked for 48 hours and stopped. So thats what you're going to face if your goal is scraping unlimited photos without using accounts.
Alternatively, you could use something like wfdownloader, and login with one account and essentially download unlimited profiles if you use the right delay. Good luck.
