Who's your internet provider?
I have Spectrum for internet and had T-Mobile for mobile. Since I had Spectrum, I could get cell service for free (or $10/mo for their upgrade anytime plan) and it was just the monthly cost of the phone. The downside is locked into the phone for 3 years, while the mobile plan is good for 2 years. Still saving $30/mo over T-Mobile.
I brought it up in another thread but if you're using T-Mobile, why not look at Mint, at like half the price? There single plans are like 20-25 bucks I think.
T-Mobile bought them a few years ago and while there are some downsides, they seem to be minor for most users. No contract either. Just go back to T-Mobile or anothever if it doesn't work out.
For single users (no family plan stuff) and users that aren't super active or in big, crowded markets where data or speed (if I'm saying that right) can push you to the back of the line, then I don't think there's much difference, if any. I mean, I know I'm not planning on playing World of Warcraft on the subway this century.