"Free" antivirus software, Windows 10 telemetry, Javascript, WeChat, WhatsApp, Google Chrome, Gmail, Facebook, and countless other software choices are used by millions of people today; that doesn't mean that feeling uncomfortable conforming to the norm is unwarranted.
The millions of people you refer to probably (without realizing) send multipart messages with a plaintext version available. Emails without this are typically spam.
The millions of people you refer to probably (without realizing) send multipart messages with a plaintext version available. Emails without this are typically spam.