Having been directly involved with all sorts of weapons tests I can attest that they sometimes go badly. The purpose of the test is to find out what does not work and fix it. If it fails in a test and you fix the problem, that’s ideal. While it’s great that the tests all work, it’s not a bad thing to have a few failures. As for the aircraft carriers (bunker fuel, by-the-way) we lose planes too. I can think of two recent crashes in the Pacific of F-35’s. As for other crashes and bad occurrences, they happen regularly. Although, the rate at which they happen to the US Navy has been decreasing steadily.
Russia knows their aircraft carrier has little utility and the reasons they keep it around are entirely political. Probably similar to the reasons we are keeping the Independence class littoral combat ships even though they are of little practical value. Politics.
Just because a weapon, say, a broadsword, is obsolete does not mean that anyone wants to be hit by it.