The "left" is no more immune to controlling thought than the right -- just look at China or the USSR
The danger is authoritarianism and centralisation, and in terms of centralisation big tech companies like Spotify have in spades. You could also feasibly argue they're authoritarian as no-one outside the company can influence policy outside of free market forces, but centralisation can make these companies somewhat immune to said forces, for instance Spotify being the exclusive distributor of Joe Rogan podcasts means those interested in his content have no choice but to continue using Spotify, even though some of his podcasts have been removed.
The danger is authoritarianism and centralisation, and in terms of centralisation big tech companies like Spotify have in spades. You could also feasibly argue they're authoritarian as no-one outside the company can influence policy outside of free market forces, but centralisation can make these companies somewhat immune to said forces, for instance Spotify being the exclusive distributor of Joe Rogan podcasts means those interested in his content have no choice but to continue using Spotify, even though some of his podcasts have been removed.