I see a lot of people requesting cellular modems in MacBooks, but the integration with iPhone hotspot connectivity is so good that I don’t really see the point of it for most people.
It's one of those small things that makes like a bit easier. On Lenovo/HP these have been around for years and they don't cost that much.
And it isn't really ironed out to behave in Germany where on a train you have frequent losses of phone connectivity. Every time it loses signal, the hotspot drops out and disconnects.
The real reason is Apple wants you to buy an ipad for on the road. Laptops, according to them, are strictly for office/home usage where wifi is available.
Anecdotally, I've also seen her get issues when going from an area with bad connection to an area with good connection (iPhone will disconnect).
The experience with a non-iphone is also not seamless, though that's to be expected.
Point being that reliable and easy cellular access on a MacBook would be a pretty nice improvement. This is especially true given how much of what people do on computers relies on the internet these days.
Dunno about that, I've been using Androids for hotspotting for years, and haven't noticed any issues.