Your argument fails when you consider Whatsapp - the biggest messaging platform, where you need to add people's number in your contact to be able to see their names.
I agree with power of defaults though. Only reason iMessage took off, and so did other Apple services.
You definitely don't... Unknown contacts show as e.g. "+1234567890 ~Bob" (their WhatsApp display name). When you save them to your contacts it switches to the name you added instead.
I agree with power of defaults though. Only reason iMessage took off, and so did other Apple services.