I’ll be the first to talk about market failures but the mere existence of friction does mean markets stop working. There’s some amount of friction with every market interaction. There is absolutely a market failing when it comes to ISPs but it’s not really friction that’s the issue, switching ISPs in an area where you actually have options is a few phone calls and scheduling a time for someone to do your wiring.
Now if every store in a 100 mile radius only had Coke, then switching to Pepsi just got a lot harder despite the two products being literal drop-in replacements for one another.
Switching to pepsi is easier as it is a single dimensional change. Switching ISP will have a multitude of effects. Most unknown (how reliable is the new one? will they give me hidden extra charges? what are their TOS? are they blocking XYZ service I need down the road? do they spy on DNS traffic?)
and so on. Let alone a decent amount of time on the phone organising it and potentially some early exit penalties.
Now if every store in a 100 mile radius only had Coke, then switching to Pepsi just got a lot harder despite the two products being literal drop-in replacements for one another.