Banning new ICE car sales in 2025 and on the road in 2030 would be about in line with what I'd expect the market to do anyway.
It seems, well, silly to be producing brand new petrol/diesel cars when there are already masses of used ones out there that will do the job.
The article talks about EVs having some small digit percentage difference in cost of ownership or whatever vs. a diesel. If it's that close, then you may as well just ban new diesel sales now.
The main reason not to would be a worry about demand spikes causing shortages.