On the other hand, from a user's perspective only one SIM card and data allotment is needed. I much prefer two devices that I would own anyway over two SIM cards with (in most cases) separate monthly subscriptions or data packs.
People won't stop buying phones because their laptops are 5G enabled. The laptop's eSIM would be on the same plan as the phone. It would help carriers to push more expensive plans with much bigger data caps, which is easy with 5G. To the point of eating some home broadband market share- I imagine some people canceling their home broadband like they've cancelled their phone landlines, which initially seemed unthinkable.