I think one of the core errors in this logic is that T1 and T4 are fundamentally different. While S9 did promise to do that in the campfire chat last go around with higher GA rates in higher difficulties the current state of the game is just that T1 and T4 are the same content at different HP an damage values with statistically minimal change in outcomes.
Also, it is inaccurate that you can skip a tier using the pit system. You do have to qualify for both T2 and T3. When you say, “skip” you mean not engage the open world, and that’s fine, but that isn’t a true skip. This matters because unlike Normal, which actually can be skipped from the start of the game where you do not have to qualify out of it, all tiers have to be proven to be beaten.