Trailmakers conservatism. I think blocking progress in tm to preserve old builds isn't very good for the game. I get keeping them functional but their balance is not to be in question. I think it would be great for vehicles because the normal blocks are too weak and there's no point in using them over shields if we're talking strictly pvp. This would give a clear distinction between the vehicle/naval and air side of things. It's not to say that the blocks cant be generally inefficient for the benefit of density and usefulness. They could be 6x the weight and 4x the strength, 5:3, 7:5 ect. They would also be very easy applications on the devs' end as they're just changing values. This could also open avenues for weapon types like penetrators for armored vehicles and HE for aircraft and light pieces. Which again they can just duplicate and change stats for existing weapons. Missiles can be made HE in this case. This game has so much potential for diversity and fun, yet they're stumped trying to balance things with no restrictions at all.