There's a rather large body of evidence that herbicides, glyphosate in particular, are, at the minimum, contributing to the bee collapse. You can find a ton of studies on the topic - here [1] is a random one that overviews some of the literature, though it's already quite dated. It doesn't kill them, but wrecks their gut biome and causes numerous issues that contribute to colony collapse. It also significant but, as of yet, unclear negative effects on the human gut biome.

Humanity goes through seemingly endless cycles of poisoning ourselves: lead, cigarettes, leaded fuel, asbestos, CFCs, and countless others. It's highly improbable that this trend has ended. During each of these cycles is there tends to be science claiming something is safe when it ultimately turns out not to be. In part this is due to ignorance/arrogance, but it's also because those who earn a paycheck driven by these issues have a strong motivation to 'prove' that it's safe, especially when it's not.

[1] - https://e360.yale.edu/features/bee-alert-is-a-controversial-...