Eventually you need new a new plane; that doesn't mean the old one is a failure. The US has only ~20 B-2s, to go with ~60 B-52s (originally built in the 1950s)

Eventually you need new a new plane; that doesn't mean the old one is a failure. The US has only ~20 B-2s, to go with ~60 B-52s (originally built in the 1950s), and ~40 B-1Bs (~1980s tech). Only the B-2 could survive war with a peer, afaik; that was fine after the Cold War when there was no peer threat but now that China is a near-peer threat, the US needs many more bombers capable in a peer conflict and the B-2 production line was shut down decades ago (production was discontinued when the Cold War ended). They plan to build the B-21 in much larger numbers. Also, the B-21 was built for conflict with China, where distances are much greater than in Europe.