Lots of local authorities are installing on-street charging.
Basically, the vast majority of people in the UK do have off-street parking. Running a cable to a garage or from a street-lamp isn't overly expensive. Those who park on public streets also have lots of options for charging.
Depending on which research you believe, only 25% of homes don't have a dedicated space - https://www.field-dynamics.co.uk/25-drivers-no-off-street-pa... and https://www.racfoundation.org/wp-content/uploads/standing_st...
Lots of local authorities are installing on-street charging.
Basically, the vast majority of people in the UK do have off-street parking. Running a cable to a garage or from a street-lamp isn't overly expensive. Those who park on public streets also have lots of options for charging.