Its certainly true that presently (2021) there are few if any financially viable EV's for towing larger caravans. There are products like the Rivian, Cyber Truck, which are closer to being released for sale. Apparently Jeep have announced and all EV off roader which will probably have a decent towing capacity but like the others its going to be costly and big.
Tesla's Model X does have a 2,250kg towing limit, but towing does affect its range. see:-
View: https://www.youtube.com/watch?v=jhX3BmhJXc8
There are the likes of and Jeep has announced a EV Wrangler, and I'm certain there will be others that will have substantial towing capacity that will suit larger caravans, but range and recharge times are going to mean a change to the traditional load up and go concept of caravanning. Route planning is going to have to include stops for charging.
I have no doubt that caravanning is going to see some significant changes. Manufacturers are going to have to put caravan designs on a weight loss plan and improved aerodynamics so they have products that people can actually use.
Based on what's available to day, most caravanner's may best served by hanging onto what they've got now, or possibly looking at a PHEV hybrid for sub1500kg caravans with the understanding that towing fuel consumption will be considerably poorer than present day diesels. But they might gain by the better consumption during daily driving. That will depend on what proportion of mileage is done solo.
One car caravanning families (I think there are still some of those) who hold onto a ICE tow vehicle may find they can't take their vehicles into an increasing number of Zero Emission Zones, or face quite high daily access charges.
Other pressures such as those who have company cars may find themselves with a problem as companies are likely to start telling employees to choose electric vehicles, which might not be able to tow their present day caravans. Their options are limited.