Here's my view:

Efuel is less efficient, simply because engines that use it are. We waste at least 50% of the energy put into it. Google also says most common cars waste between 60-80% of the energy. This means while Efuel is net zero in terms of production, assuming the energy put into creating it is all clean and 100% efficient. If we view the production and use of efuel as a cycle, you're wasting half the energy every time. Every time the tank is fueled.

Electric engines generally waste roughly 20%. There's some additional loss across the charging of a battery, but it's still far better than a gas engines efficency.

The problem is the energy and waste from battery production, which makes them worse than gas car manufacturing. But they pass gas cars as long as they are used long enough. And here's the important part, we can improve and change batteries and their production process. We are seeing massive research into this and especially into batteries not involving rare materials. We can also improve recycling of batteries. These are all things we can do to avoid oil and gas. Because gas engines are less efficient, and even with Efuel as net zero, the process of production and loss in use is just worse than electricity based use.

And electricity can be clean energy. If we just find better batteries, we can move to a much cleaner process. But a long as we remain on inefficient gas engines, we will always have co2 pollution, along with other pollution. Eg. If Norway with 98% clean electricity swapped to all electric, and battery with the car got on the same level of gas engine in terms of production waste/pollution, we'd be saving so much energy and waste because of the much higher efficiency of electric engines, and reduction in gas use. Efuel can never do that, it will need green energy for production, and waste more energy in use. Thus I see no reason to push this over electric vehicles.

There's other downsides, such as heavier cars cause more road tear and air pollution. So ideally we'll also move away from cars as much as possible. But trains, busses trams and so on can also be all electric and thus more environmentally friendly.