Older instruments sound better, ate this true and why

I think for electric basses it's a total package, for instance fender early pre c s 60's jazz basses are way more sought after than 70's mainly because of the quality & the electronics. W/ double basses & tone woods "Open up" & developed over time. But there are alot of 200 year old double basses that aren't worth more than $4000 just because they aren't very great basses the are just old. Usually older double basses are worth money just the same way because they are old & there sound has developed the maker is probably dead & gone and not producing instruments anymore.