There is an episode where a new game is brought on board. It's really enjoyable, and once people start playing, they don't want to stop. Soon, the whole crew is addicted. It turns out the creators of the game are using it for mind control.

Seems like the perfect metaphor for modern cellphone/app usage.

https://en.wikipedia.org/wiki/The_Game_(Star_Trek:_The_Next_Generation)

Data: Captain Picard, we are being hailed!

Picard: don't put video on

Data: but they want to video chat sir

Picard: text them "what's up"

I dont think that in the 60s-90s anyone would have necessarily anticipated the existence of smartphones as they are now. Rather than it being a “deliberate” choice not to have them in the show. Its just not a futuristic idea of communication that existed at the time. Theres not smartphones in The Jetsons either. Earlier ideas of what the future would be like were a lot more utopian than the dystopian hellscape induced by smartphones and social media. Their various ideas of the future were a modification of the way people actually lived then, which was simultaneously less connected but also more interpersonally social. They dreamed of a more connected future, but not one where that level of connection would rip apart established social fabrics

They have communicators and iPads.