I agree with Raywood earlier comment: We will see more and more cities,towns or conglomerated areas introducing LEZ's and other measures to reduce vehicle usage and to increase revenue for the local authority.
The prime issue is too many vehicles trying to use limited space in towns and cities. This has two main effects congestion, and poor air quality which is made considerably worse by the congestion.
Otherclive made the point that authorities now have a lawful duty to control air quality, but they only have limited tools they can use.
Obviously the best way to reduce pollution is to limit the use of processes that produce it in the first place, in this context that means identifying the sources and either stopping them, or cleaning them up or reducing the number of them.
We tend to focus on vehicles in this forum, and that's understandable, but when restrictions fall on us we obviously see and feel them more intimately and are perhaps not fully aware of how the measures affect other people or businesses.
Air quality has been an issue for some areas since the beginning of the Industrial Revolution, For example the area in the West Midlands and South Staffordshire which is known as the "Black Country" got is name due to the way the whole area was smothered with dust and debris from the uncontrolled pollution from the industries that sprang up there. There are similar stories across country and beyond.
The London Pea Souper fog of the early 1950's were noted for causing about 12,000 premature deaths annually in the city. This prompted Parliament to begin formulating the Clean Air Act introduced which was introduced 1956. It was further enhanced in 1968 to prompt more local authorities to do more to reduce smoke. By about 1980 the skies were much clearer from burning coal. Further tightening of smoke regulations were introduced in 1993 and have continued to be revised.
But along side this the numbers of road vehicles have been ever increasing, Back in the 1950's cars were probably far more polluting than todays ICE vehicles, but there were far fewer of them, so their impact on air quality was very small compared to the levels from coal fires etc.
But as time has passed the numbers of vehicles has grown massively, and whilst individually they are all probably far cleaner than the mid 20th century vehicles, the numbers have grown so much that they represent a somewhat bigger proportion of the pollution than before, and that makes then a target for intervention.
Certain types of pollution have been clearly linked to poor health, so it makes sense to try and reduce these emissions, especially where there is a high population density, and natural means of mitigation are limited.
I believe it is almost certain that over time further restrictions will be applied and ultimately (maybe a number of decades away) we will see a very different picture of how motor vehicles can be used.
If nothing else, the Covid-19 Pandemic has demonstrated two things very clearly. The first was how pollution dropped during the hard lockdown due to the vastly reduced number of vehicle journeys, and how we don't all need to travel to a place of work every day.