We have an MG dealer service bay opposite us on our business park. It used to be Subaru but they were having problems with customers just going away as the range is not what it was. Since they took on the MG franchise (3 years?) it is clear their business has grown significantly as they have approached everyone on the park to see if they can have spare parking slots. I pass their showroom on the way in/out and it is a lot busier than it was. MG is doing well for them if that helps.
The electric car market does seem to be causing a re-order of the popular brands, it will be interesting to see what happens when the UK starts to see Chinese RHD models start to appear.
I had a Subaru Outback with the dual range manual gearbox from 2002 to 2014 when it got written off in an accident. It was a great car and I loved being able to put it in low range and reverse the trailer easily around the side of the house. It was pretty worn out at 247,000km but I had only just replaced the clutch, amazing that the first clutch lasted so long. If the new model had the same dual rang manual gearbox i would have bought a new one but as you say they lost all their customers as the range is not what it was.
I agree the electric car market will cause a re-ordering of the popular brands with a few new ones mainly from China and maybe a few disappearing. I think Toyota is currently the best selling car in the world but people are thinking they are going to be finished soon. I agree they seem to be lagging behind in creating EV's but their Hybrids have probably saved the world of more CO2 that Tesla because they have been selling them for so long. I feel they are going to be successful with their solid state battery and take over as the best selling brand in the new EV world at some stage.
