- SFUs can record / intercept the stream
- SFUs can censor or change the stream
That first one, I think, is actually a benefit for some applications. But I'm a bit curious why the article points out P2P is free and then use "cost" as a reason for SFUs.
Also, from experience, P2P is not that simple to setup when firewalls are involved. So that is one instance of the article where it actually oversells P2P (in an article clearly written to sell SFU).