Yes, but social media promotes things toxic people say because it generates revenue. They are part of the problem.
Lemmy and Mastodon are social media as well, and they are not profit driven. Non-social media like newspapers and cable TV also spread toxic content.
In the end, you got the causality reversed. Media (both social and non-social) gravitates towards what drives the most engagement. Negative/toxic content drives the most engagement because that content elicits a strong emotional response in the consumer.
Media amplifies the problem, but ultimately the problem is people. Toxic content is going to stick around until people stop giving it attention, and unfortunately in all of the history of humanity we have yet to figure out how.