Just wanted to chime into some of the comments I am seeing as I'm currently connected to this field. First off, Level 3 direct current fast chargers can typically get a vehicle to 80% in 20 minutes. When traveling across the country, this type of fill up is the method people use. The charging network companies (Volta, Electrify America, EVgo) have a lot of data to support this.
Someone also mentioned placing the chargers at chain restaurants. This strategy is already in place. I've mostly seen agreements with grocery stores, banks, and convenience stores, but quick service restaurants make a lot of sense too.
In the next 3 years, the big buildout will be coming to offer EV stalls at side of the highway gas stations and truck stops.
Even with me being in the industry, I don't yet have an EV, so I can't weigh in on the convenience, or lack there of, on longer travel. It is my understanding that taking a 20 minute break every 250 miles is a trade off most people accept over having to drive an ICE vehicle long distances.