Hi,
Airplane mode is designed to be used in airplanes.
There is generally no service in an airplane so it turns off your cellular, (my friend told me that 5G can interfere with the pilot's equiptment so that is why they have it but I'm not sure.) If the plane you were in had WiFi, then you would get texts from everyone. (I know for sure that Southwest had a free texting option, but I'd check to see with other airlines if they have it.)
If you are using airplane mode on the ground, a better option would be to enable focus assists, by going into settings--> focus. you can create a focus status by pressing the + button in the top right corner, and then choosing what people and apps you would like to give you notifications during the focus.
Hope this helps!