All of those could be good ideas, or not. If they were serious suggestions, then you'd commission research on them, rather than just pick it out of the air for no reason than it sounds like it might be a good idea, which is what they're doing here.
I'm not suggesting that the 2 year idea isn't a good one, but all it is, is exactly that, an idea. They've not said how it would work. The cost of living crisis is now, so would anyone due an MOT soon be allowed another year without one, so suspending most MOT's (apart from the 3 year old ones) for that period? If it's based on your next MOT being valid for 2 years, then any saving would be at least a year away. Do they make the MOT more stringent (Are the tests you've highlighted above in other countries stricter?) to allow 2 years wear and tear? That might put immediate costs up for people getting their car tested?