Yeah, I've heard so too from a couple of experienced lifters.
Mine have always been kinda big and I never even train them anymore.
I've also heard that what got many of these guys' calves growing was not typical BB work or even weight training like calf raises, but instead stuff like hill sprints, jogging at the same place in a sandbox and stuff like that.
Wearing a belt will not save your back imo.
It can function as a reminder to brace your core (at least that's the way a belt work for me) and that can help you get a sturdier "base" to lift from (which can lead to more weight on the bar), but if you're technique is off in a way that causes excessive pressure on the spine, a belt will not fix it. A bad position is bad, no matter if your core is braced or not.