I was thinking about it a bit more this morning, in Costa Rica I used a local sim from a local carrier, but since then I've been traveling but using esims from Airalo, they still use a local carrier, but I wonder if it's kinda like how the 2 factor auth stuff often won't let you use a VOIP/twilio number it needs to be from a real carrier, I wonder if x has a matrix of signals they use to decide to switch it or not, and within the carrier metric, esim re-seller is deprioritized over a real telco or something? Who knows, but it's kinda fun to think about! :)