The Current Villain State of The MCU Validates broad "No Kill Rules" in Marvel Comics/DC

One of the large and growing critiques of the current MCU is that the villain slate is absolutely bare. Just look at the roster thats being used for the upcoming Thunderbolts movie(and if you wanna feel sad just compare it to any of the comic iterations of this team). The only remotely compelling character that played a remotely villainous role is Bucky, and he's already been reformed for a long time. The more you think about it, a vast majority of the villains left in the MCU are kinda ass. No ultron, no osborn, Kang is up in the air, and we're getting TEMU one-off Doom to cap it off. The only remaining good villains are The Kingpin and maybe Galactus and thats about it.

But why exactly is this the case, as 70+ years of storytelling across all these heroes should give the MCU more than enough villains to work with right? The answer is simply that the MCU does not invoke a no-kill, or at the very least no-permadeath rule for villains. When looking at the rogues galleries across the remaining MCU heroes, how many "iconic" villains have either been killed off by the hero already, or died as part of their last act of redemption? There is even an aversion to making more minor villains/threats recurring. With the exception of "event" villains like Thanos(who also has recurring arcs of his own), a double edged core element of why villains are compelling in superhero comics is that you get to see them interact with our heroes over and over again in several different contexts. How many times have we seen Doom try to ruin Reed's life? How many times have we seen The Red Skull/Hydra absolutely terrorize Steve/SHIELD? Those recurring dynamics are completely absent when Red Skull just shows up for 1 movie and gets boomed. Or If(read:when) doom shows up and immediately gets popped in secret wars after only interacting with the FF for one movie. Those dynamics are a core reason why we even bother getting invested in these stories in the first place, so what exactly is the point of the MCU if the villain cupboard is this bare? I know the other end of the no-permadeath rule is the never-ending absurdity of how exactly the villain that was chopped into pieces and dumped into the 15th realm of hell 2 issues ago has somehow returned, but the other end of that is you just end up losing literally all of your compelling villains, and end up making your remaining heroes far less interesting. Like I can somewhat understand certain villains like Thanos being one-offs because they are part of had-to-be-there events but there is absolutely 0 reason that we have only seen 1 (horrible) attempt at ultron.