GSM dongles simply aren't that popular anymore. Wifi access is near-universal, so the average consumer will pretty much never be without internet access - and their phone is a pretty suitable backup hotspot. The people who do need GSM-based internet - like surveyors or door-to-door people - are probably better served by tablets anyways, and definitely don't want to deal with a USB dongle. If they have to, they'll jus…
I do think 5G has been slightly miss-sold. Its main benefit is using the higher frequencies which have shorter effective range, so a busy location like a railway station that has thousands of people in can more effectively split them into microcells. But in most cases a "5G" phone is going to be using 4G infrastructure for a long time.