[warrenm]

What "modern smartphone" cannot "play music smoothly"?

If you mean, "can't stream smoothly" - check your connection and your service choice (eg Paramount+ always seems to have problems for me ... regardless of the connection or device)

But "play music smoothly" has been a core feature (with nary a problem) since the first iPhone

Every one I have had runs all the audio I have ever wanted to run with no issue - 4G, 6S+, 8+, 11, SE, 14, and 15

My dad's and mother-in-law's Pixel 7 also have no issues