I only have experience of the Mitsubishi Outlander PHEV. In my experience with the vehicle I personally wouldn't buy one for towing a caravan even though it can, like many other cars.
As I suggested earlier, if that is the sum total of your experience, then all you can really say is you don't find the Outlander to be suitable for you. However there may be others that might suit you better.
A lot might depend on how the system is set up, as there are different approaches. The Outlander ICE engine is simply there to produce electricity to run the electric drive train. Where as other manufacturers have opted to have the electric motor supplement an ICE engine and transmission.
There are different gear box arrangements, Some just take electric power with a fixed ratio transmission and no need to change gears, Others use CVT, and other retain a conventional multi ratio gear box some are manual but I think most are auto's.
It is my view, with the exception of Tesla, we do not have an adequate EV charging network up and running in the UK. It is continually improving, but it still does not make it easy to consider longer journeys or towing with EV's. There are major advances in the pipeline that will make significant improvements in the battery technologies which will allow for greater energy storage and faster recharging times making EV's a realistic alternative, even for towing.
Until we have a reliable and consistent charging network , there is in my view still a case for Hybrids for a number of years after which they are likely to phased out as the charging network improves.