- "iPhone's are generally more expensive, Android phones are generally cheaper", so having an iPhone signals financial "goodness". Same argument can be applied to lots of other products.
- "iPhones are generally better, so if you have Android you're compromising for some reason", e.g. lack of money to buy one, "weird" political/social/other beliefs, etc.
- Messaging systems are like accents; some people might prefer dating someone who speaks their language in a more similar accent, and others might prefer dating people who use the messaging system they prefer.
Also, a lot depends on your definition of "shallow".
I'd thought of the money one, hadn't thought about the possible signaling of "weird" beliefs.
The third point seems a little silly at first, but reflecting on my own musings on whether to go full Signal-only or not I guess I can imagine someone being iMessage only same as some people are Signal-only.
As an Android user, I'd counter "Signal". Which I think would bring things back to what another comment mentioned about preferences in messaging platforms.
- "iPhone's are generally more expensive, Android phones are generally cheaper", so having an iPhone signals financial "goodness". Same argument can be applied to lots of other products.
- "iPhones are generally better, so if you have Android you're compromising for some reason", e.g. lack of money to buy one, "weird" political/social/other beliefs, etc.
- Messaging systems are like accents; some people might prefer dating someone who speaks their language in a more similar accent, and others might prefer dating people who use the messaging system they prefer.
Also, a lot depends on your definition of "shallow".