In principle this is a good idea.

In practice ... there is always so much bureaucracy and inertia. I don't think the current EU model works well. I also don't think a copy/paste USA 2.0 works either, yet this seems to be the primary objective by the people in Brussels (that is, = politicians, not all folks in Brussels of course). There is such a huge disconnect between what people such as Leyen babble, and what people want or need or may want. And a lack of decision-making power too. So I think most of those projects will end in failure.

Personally I think an EU model will only work when the agendas are NOT unified, because unification leads to disagreements. You can already see this happening in regards to politics or war - some countries want to, oddly enough, serve Russia. That may be a fine decision for a state, but if other states push for another approach, you have a problem here. Now there are discussions to simply isolate the "non-compliant" states, but this is a bad approach since it will again lead to fragmentation and more people being angry at Brussels here. So this is a failing model. Splitting up things into separate aspects will also, of course, lead to more bureaucracy, but states would more easily form a specific opinion and align towards that, without being handicapped by other states that don't want to go that route. I don't see any other way for this to work. The EU in its present form is just setup for failure - the current model simply does not work, and the proposed new model is even worse in many ways e. g. 2/3 majority basically means that the big states will dominate the small ones. For instance, if Germany and France want to go to war against Russia (let's assume this were the case), then they'd have to send troops to the front - and they are unwilling to do so. So other states are more likely to be threatened. That model not only does not work but is also unfair.

Of course legal or taxation models are different to war, but the different countries have different wealth and opportunities, so a one-size-fits-all also can not possibly work. We saw this with the EURO where weaker countries struggle permanently. The whole EU needs to be completely re-designed - and this is not going to happen due to inertia alone.