You’re right but the problem there is that nothing changed for the worse, aside from more enemies to deal with at once ofc. Positioning, awareness and mobility has always been more important for psykers than the rest due to their low passive defenses.
But what the weapon & blessing changes and new talents did do, is exponentially increase our options to deal with it all. The absolutely insane toughness regen lets us facetank ranged and even the occasional melee as long as we keep topping it via warp kills. One With the Warp among a few other nodes do add toughness dmg resistance, and there’s always the shields too. And I already went over much of the rest.
I guess what I’m getting at here is that overall things really did not change for the worse for psykers, but the opposite. But all classes are designed around performance, and this is especially true for psykers. Almost all toughness regen and talent & blessing procs are based on hits, crits, kills, or peril buildup. This includes the effects stagger, suppression and kills themselves have ofc by just reducing the enemy offense in return. So the more aggressive you are and the more impact you have, the stronger your defenses become too.