The impact so far proves to be zero. Because all the teams understand that the Nations League was invented instead of the usual friendly matches. That's why everyone treats these matches as friendly matches, where the coaches have the opportunity to experiment. I think the situation with these competitions will not change, because every two years there are more serious competitions.
But in a way, this is also in UEFA's interest, as it could make smaller teams able to increase their level of competitiveness.
That is, for France, Portugal, Germany, Italy, it may not be of much interest. But for smaller teams, it could be a good opportunity.
When this tournament is used as a place to try strategies for big teams, then at least they can still play with good results. Because trying several strategies doesn't have to mean they always fail because the opponent is a weaker team, even though it's good for mediocre teams but that doesn't mean they can win easily. But yes, there is nothing more that can be done because everything has happened, I just find it difficult to accept the results obtained in this National League because as a big team of course they have several advantages even though they are trying a strategy at least they can still survive better because they have a squad with better quality.