Cost-effective might not be the best description. If the B2 is able to target SAMs with very low losses, then it could still be cost-effective compared to significant losses of other airframes and crews.
Cost-effective is the best description. It doesn't have to be a totality. For total operation costs (training/missions/acquisition/maintenance/capabilites), the B-52 is cheaper by orders of magnitude.
The B-2 does have its place and is better suited for certain jobs, albeit at too high a cost. The B-21 is purported to lower that. We'll see.
Edit: Looks like current B-2 operational/maintenance costs are now down to only about 2x that of the B-52, which is an impressive reduction (no sarcasm).
With eight engines mounted on external nacelles, it is the complete opposite of stealth. You need complete air superiority to use it without fear of being shot down.
The eight engines is a side effect of of how large the aircraft is vs how big the engines of the day were. they are basically business jet engines by modern standards.
During the recent engine replacement project using one full sized engine per boom instead of the twin small engine nacelle was seriously considered. So 4 engines instead of 8. I suspect the reason the twin nacelle was kept was that going to 4 engines required more engineering rework than they were happy with. It certainly would have improved the b-52's range and fuel efficiency.
Either way probably a net zero on the stealth consideration.
Fun fact: with the re-engine project the b-52 now has the same engines as the A-10.
You're still only talking about the cost side. You're not talking about the effect side. So they're 2x the cost, but how much did they save in reduced casualties?
One does not simply take out a SAM system with a cruise missile, especially when that SAM system can also target the cruise missile. So how do you get a cruise missile to launch from the right spot where the SAM system radar can’t see it coming?
Sure they are - the s300 system for example can be redployed quite rapidly & some like Buk have the radar even integrated with the launcher.
Also only the radar really transmits, so even if you hit it the, separate launchers might still be intact & guided by another radar if you don't destroy them.
This is why modern remotely guided middle strike drones are so dangerous for SAMs - they can basically search an area for all the SAM system components and destroy them all or most of them. Potentially much more effective than a homing missile hitting just the radar at maximum.
The b-52's role on the modern battlefield is basically a cruise missile truck. It lets you launch a bunch of cruise missiles(cough, I mean kamikazi drones, gotta use the modern lingo) from random locations.
The B-2 does have its place and is better suited for certain jobs, albeit at too high a cost. The B-21 is purported to lower that. We'll see.
Edit: Looks like current B-2 operational/maintenance costs are now down to only about 2x that of the B-52, which is an impressive reduction (no sarcasm).