<p><span class="h-card" translate="no"><a href="https://mastodon.social/@whitequark" class="u-url mention">@<span>whitequark</span></a></span> The SMS protocol kind of supported read receipts (actually "delivery reports"), but Apple was really the one to popularize the feature AFAIK. It was in the very first version of iMessage in 2011. Telegram didn't exist at that point, and WhatsApp didn't get them until 2014. Apple converted a huge proportion of U.S. texters to iMessage, so they associated texting with read receipts by default.</p><p>I've also never used iPhones, which is probably where some of my disconnect comes from.</p>