"Rivians network, anyone's network, will be very profitable if it can achieve high utilization." - Agree -but the RAN which it absolutely cannot unless and until it opens up to the public (at which point it's even more of a distracting side gig)
"Tesla's charging network is contributing massively to Tesla's profits." - It's not even close to break even actually in and of itself. Sells cars though!
"Comparable to current gas pump deployment) will be providing the base charging network for the US." - Agree, and in fact somewhat oversupplying the market for a few years. Even when there's 100% EV adoption there will never be a comparable number of EV fast charging stations to gas pumps. (People don't have gas pumps in their driveways - but they do have L1 chargers.) There'll be something like 15 - 20% as many DCFC as there are gas pumps. More if young people stop owning cars and it's a more Uberish world.
"I'd see Rivian's network more as an advertisement for it being an off road EV. Put them at trails end type locations that bikers use for going off road, that type of thing where the NEVI chargers may not get to but high income demographic drivers do." - Agree. Their level 2 destination charging at trailheads etc., makes a fair bit of sense and you can build, oh, call it 40 level 2 parking spaces for the cost of one fast charger. That's why I'm only saying the fast charging part will go away.