Why can't I send SMS to Android phones from my iPhone 14 Pro Max?

Did you set up Messages so that it automatically tries to send messages as an SMS when iMessage isn't available? Go to Settings > Apps > Messages, and make sure, that "Send as Text Message" is enabled.

In addition to the advice that Ingo2711 has provided, check with your cellular provider to ensure that your phone has SMS/MMS provisioned on the device.