My 10 year old EV has a button on the steering wheel that will show all the chargers it knows about within range.

If planning a route using the built in satnav it will say "you won't make it, add a charging stop?"

But there's so many chargers I don't even bother planning.

I’m afraid these calculations are more tuned to sweetheart deals the car manufacturer has with the infrastructure owner than to my best interests.

Tesla will 100% route to Tesla chargers, which is what you want to use right now. Maybe in 5 years it will be worth thinking about other brands.

Only Tesla does that.

That is false.

This integration didn’t exist when the EV versions were just electrified versions of ICE cars.

This changed with the upcoming of car by traditional automakers that were designed to be an BEV first. I’ve used the route planning in a Kia EV as well as a VW EV without any issues. You can plan your route with charging points, select the desired remaining capacity, select the kind of charging you want, etc. AFAIK Porsche offers the same features too

That seems weird.

Edit: Just looked up Porsche and they have it too. They call it "Intelligent range optimiser". Can't be asked to check more brands.

My Renault Megane E-tech will tell me the battery % when I reach my destination, and will ask me to add a charging stop on the way if I won't make it. My previous BMW i3 did the same.