"Is this the end" is a daft clickbait question. First, what is "this"? Secondly, what is "the end"? Thirdly, if by "boutique" you mean custom built basses, then of course it isn't. As long as there are people wanting instruments built to their own desires and specifications, and as long as there are luthiers willing to build them, then there will be 'boutique' basses.