In practice sub-6 bands are just good enough in most scenarios. We're 5+ years into mmWave deployments in the US and there's still very little interest or regulatory push worldwide.
For instance it's completely stalled in South Korea which has one of the highest 5G coverage and market penetration. In Japan I found articles from 2023 claiming the mmWave coverage was "0.01%" then, I don't know if it expanded in the meantime. In Europe there's virtually zero production deployments or devices sold with the compatible modem/antennas. While there are small deployments in Australian cities, Apple doesn't bother selling compatible models. Etc.
For instance it's completely stalled in South Korea which has one of the highest 5G coverage and market penetration. In Japan I found articles from 2023 claiming the mmWave coverage was "0.01%" then, I don't know if it expanded in the meantime. In Europe there's virtually zero production deployments or devices sold with the compatible modem/antennas. While there are small deployments in Australian cities, Apple doesn't bother selling compatible models. Etc.