He was a complicated figure. Like many of the Russian opposition figures he wasn't necessarily a bastion of liberalism- he was racist and fully immersed in the Russian imperialist mindset of Russia's near neighbors.
The documentary shows that part of him of course. It doesn't just lionize the man. But I think everyone should watch it mainly for the glimpse into how the Russian state operates. The assassination attempt and denial showcases the worst aspects of the Russian regime and how it treats enemies of the state.
We are seeing this all now. Putin killed Navalny in prison. He blew up Prigozhin. The anti-war presidential candidate Boris Nadezhdin was disqualified from the March elections this month. This is Putin's Russia.