Can there be technical things why cerain services get lower level service?
I’ve read that ISP buys various links to to other networks at various prices.
So maybe something like: if facebookBar server is on pricier linkFoo and for that reason ISP buys cheaper version of linkFoo effectively downgrading facebookBar service (along with everything on linkFoo)?
If such scenario is realistic, maybe it could be due to valid financial stuff, not due to anticompetetive behaviour. (Just saying, some technically valid scenarios should be taken into account)
Transparancy (at least how I see it) is matter of culture.
For example, if you open up ISP accounting books to the public, creative people will find ways to hide things. Instead of line item “10M € kickback from facebook”, there will be “10M € sale to facebook”.