Gear/renown Disparity is main issue with t4 scenarios that I see. You can usually tell the outcome of a scenario just by inspecting people. If you don't see near Sov level of gear and people potted around you, expect a quick loss, regardless of player skill levels/coordination.
The issues that exist in t4 scenarios do not really exist in 1-39 scenarios due to gear gap being relatively less of an issue. I don't think I have ever seen a 1-39 scenario as terribly lopsided as the t4 scenario geared stomps have become and skill seems to be more important than gear in this bracket. Anni vs duelist gear is not that big of a difference and with a bolster being under leveled is not a huge issue.
A SoV 40/80 with consumeables is easily 300% more powerful than a 40/45 conq geared character without consumeables. So the winner of t4 scenarios is often the side with the highest overall gearscore.
In the recent past vanquisher gear was only 30-35% more powerful than conq gear, in terms of gear points. Now the gap has widened Sov being 110% more powerful than conq gear atleast by using the power level chart
viewtopic.php?t=49367 . I made the mistake of trying out a fresh 40 the other day in t4 and it was honestly one of the worst experiences in gaming I have had in a while with little ability to defend myself or make an impact in the scenario whatsoever. How many new players will be willing to get stomped by established players while they spend months gearing up?
The gear desparity easily allows a few established players to crush the newer players and snowball a scenario and made me feel like queing my fresh 40 as causing my side to auto lose.