That’s crazy to me: they already have to go through certification for the 2.4GHz stuff, why not include a lower wifi standard in there (for the 2.4GHz band)…
It's probably for power reasons, the nrf series are really great on power consumption.
Yeah, if you look at a flagship nRF52840 board like the Xiao Seed, it ships with an integrated lithium charge controller, and just 5 μA power draw in deep sleep. If you are building any small battery-operated device, it's a no-brainer
I had to choose between an ESP-based and nRF-based MCU for my MeshCore node, the power consumption between the two made it obvious the nRF one was the way to go for a solar-powered repeater.