Let's Encrypt issues certificates for almost 30% of web domains, with over 47 million domains protected. The organization's automated certificate issuance process has led to a significant increase in the use of HTTPS on the web. However, the analysis also found that many websites still use outdated security protocols, such as RC4 and TLS 1.0. Additionally, some certificates have extremely long lifetimes, with thousands expiring after the year 3000.