We can't agree with the chilli peppers, they seem to get more embarassingly awful each year. They're not trying anymore. We don't agree with The Smiths either, the last album was still great but not quite up there with the others IOO. Certainly not better. A lot of our favourite bands go through a lull then come back with something fantastic, like Sparks or XTC. The latter unit's songwriting definitely improved over the years. About 70% of Andrew WK's second album displays his evolution, a lot of us still keep hearing new bits, the production is just godlike. But then we knew he was 100x more talented than all his MTV peers anyway.
Big Black, Killing Joke and The Birthday Party all attained the most critical acclaim for their last/latest albums, though some prefer previous efforts. Tool for sure.