They did a road trip in a BMW i3 which is basically a commute car. And their point does stand - if you like cars and road trips enough to watch GT or Top Gear you probably care a lot about being able to make road trips.
For my family, it means owning my i3 for commuting and my wife's Toyota Sienna for family trips. For others, it could mean renting a car for a week or two when you take a long road trip.
As a fun note: As a BMW i3 owner, BWM offers me up to 2 weeks per year of complimentary gasoline car rental for road trips.
The GT people have standards which don't really apply to most people. Most of their shows involve cars that most people will never afford.
There's a pretty big assumption that travel beyond 60 miles (or 110 in the case of my i3) requires a car. There are a lot of ways to travel that don't involve driving. I travel frequently; it's almost always by air.
I don't know about that. They do it just to shit on EV's. (Disclaimer: I own an EV, but also like and watch Grand Tour). It's an entertainment show. They're not about objective analysis. It's the crank-call-radio-morning-show model applied to cars.
Their complaints about the i3 was low range (needing multiple recharges) and weak power (when range extended).
They could have used something like a Vauxhall Ampera, which is actually designed for the road-trip route they ran (all electric in London, powerful gas range extender for freeway driving at 80+mph).
They could have used a pure-EV car that actually had decent range like a Renault Zoe, which would have only needed a single recharge stop to make their entire trip, even driving at 70mph the whole time.
But they didn't. They didn't use a fair car to test, because then it would have been less funny.