Do you think that the Japan economy crisis in the 90s caused most anime that were created in the 90s to be darker in tone and mood?

I have a theory that the reason why most of the anime that were created during the 90s were so dark in tone and mood was due to Japan economic crisis during the 90s. In the 80s, most anime that were created during that decade were so optimistic in tone and mood was due to the economy that Japan had during the 80s. Then in 1990, Japan’s economy crashed and did we see a shift in tone and mood in anime going from optimistic vibe to a darker and more introspective vibe. Do you agree with this theory, why or why not?