I assume it's a deliberate choice. Where I live these old prepaid contracts are still available next to the offerings you describe and are preferred by some older people and minimalists.

In Poland, I pay 25pln (~$7) per month for unlimited calling and texting + 24GB[1] per month I think.

The fun part is that the data rolls over, so I have something like 4TB of unused data right now, + whatever the special bonus pool I get with each top-up.

The gotcha of this promo is that it all resets back to 0 if you forget to top up even once. I put one over on them though, my bank has an "auto top-up" feature, which is completely free, and of which I'm a very happy customer.

[1] It's 15GB for the first month of the promotion and then it rises by 1GB each month until some cap. Not sure exactly what the cap is though, as the data rolls over and I'm using some each month, so it's very hard to keep track of.