Standard Python requests library achieves roughly 2% success rate against Amazon's 2026 anti-bot system. Switch to curl_cffi, which mimics browser TLS fingerprints, and success climbs to 94%. That's a 47-fold improvement from addressing a single technical layer most developers never see.
The gap exists because modern systems compare what clients claim to be against what their TLS handshake reveals. Claim to be Chrome 120 while sending Python's TLS signature? Instant block. The Client Hello message, sent unencrypted during TLS negotiation, exposes version, cipher suites, extensions, and elliptic curves that uniquely identify each HTTP library.
Detection happens at the protocol level, before application logic even runs.