I use aires en route to another location. Most of the time my UK trips are within a direct drive from home, so I have no need for a stopover. I simply go to a site. I understand people's desire to overnight on the cheap but the cost is not high in the scheme of things (just more visible).
The UK is geared for caravanners, so many sites are off the beaten track and you'll need to walk/cycle/use public transport or pull a Toad. The motorhome-friendly sites (on the doorstep of something) are so oversubscribed that you need to book well in advance. Spontaneous visits are not assured. So UK outings tend to be planned and booked ahead. 2020 is already sorted. Now planning for 2021.
In comparison, continental camping is a breeze.
The UK is geared for caravanners, so many sites are off the beaten track and you'll need to walk/cycle/use public transport or pull a Toad. The motorhome-friendly sites (on the doorstep of something) are so oversubscribed that you need to book well in advance. Spontaneous visits are not assured. So UK outings tend to be planned and booked ahead. 2020 is already sorted. Now planning for 2021.
In comparison, continental camping is a breeze.