Carboniferous rainforest collapse and animal evolution

This 19 February 2020 video says about itself:

The Carboniferous Rainforest Collapse set the stage for a takeover that would be a crucial turning point in the history of terrestrial animal life. If it weren’t for that time when the rainforests collapsed – in an extinction event that you probably haven’t heard of – our ancestors might never have made it out of the swamps.