A government condition of the merger was that T-Mobile had to offer low-cost prepaid plans without an MVNO. The program is called T-Mobile Connect, https://clark.com/cell-phones/connect-by-t-mobile/ & https://coveragecritic.com/t-mobile-connect-review/ & https://prepaid.t-mobile.com/connect/phone-plans

Monthly price for USA-only unlimited talk/text + 5G/LTE data, is $15/5GB, $25/8GB, $35/12GB + taxes/fees.

Outside USA, T-Mobile pSIM Wi-Fi call/text continues to work with cellular/eSIM data from 2nd line.

Eskimo has 2y ("global", excluding Argentina, Brazil, Chile, Qatar, Maldives, Morocco, Oman, Portugal, Singapore, South Africa) and 1y (regional) data eSIMs for about $4/GB, https://www.eskimo.travel