For software that opens dozens of threads at once, addresses from open lists fail on the first requests. A closed pool with SOCKS5 and HTTP spreads requests across thousands of addresses. For tasks like these, people choose private addresses with spare threads. Details: https://telegra.ph/HTTP-Proxy-Service-11-10 Addresses come from all over the world and traffic is unlimited. Traffic is not billed by the gigabyte. For private Socks5 proxy the software connects right away.