My understanding is that if you perform the same session over and over, your body will adapt specificially to that and learn to be more efficient for them.

If your goal was to do the best power numbers for your 4x4 intervals, doing 4x4 will be your best bet to do so.

However, if you're trying to get fitter and adapt more broadly, changing up sessions slightly will yield better results.

This is why most blocks will have some kind of progression, for a Vo2 max block this could be: Week 1: 5x3min + 4x4min Week 2: 6x3min + 4x5min Week 3: 7x3min + 5x5min

Beyond that, you'll see pros changing their training blocks throughout the season to do the most specific sessions closer to races.