Probably the builders putting in the cheapest toilet they can buy has something to do with it.

>Recent revisions to the 2023 National Electrical Code (NEC) — specifically Section 210.52(C) — change how receptacles can be installed in kitchen islands and peninsulas.

>The updated code removes this allowance in local jurisdictions that have adopted the unamended 2023 NEC. In those jurisdictions, receptacles located on the sides of islands or peninsulas can no longer be installed to meet the required countertop outlet provisions.

You can have pop-up ones but that would be a builder choice.