I know this is months old but thought i'd respond.

I definitely disagree with how you value nature. Sure your examples provide context for certain species or incidents but they don't work as a generalization and its fairly dangerous to think you understand countless creatures intent and quality of life, then decide the best outcome would be if they didn't exist in the first place. As the next step is preventing the continuation of existences to prevent suffering which is straight up gatekeeping life.

I would argue that you cannot define the foundations of your values of nature with real data, only theoretically due to the fact each individual in nature will have a different experience. So it has no capacity in deciding the value of life in a natural setting outside of an individual.

And the fact you say "one can see nature is bad for most sentient beings" is confusing.

Nature is the collective lives/choices/adaptions/competition/symbiosis of individual beings, be it plants/animals/fungi/insects and many of them are thriving when undisturbed by humans. There is no natural foundation for nature, there is nothing natural about nature if you give nature self agency. So one aspect of nature may find substance and "good" at the expense of another aspects suffering "bad", and who gets to decide which aspect defines nature more.

So to define nature as bad for sentient beings is speciesist, as it is truly saying wild creatures are bad because you don't understand them unless you speak of this in relation to a certain ecosystem or species. Because nature provides all aspects of life and varying depths of emotional experiences to a plethora of individual entities which is ignored when you say "nature bad"

Also if we are to define the significance of ones life solely on how painful their deaths are humans within society end up in some pretty dark places extending life unnaturally, not to mention war...

You cannot conclude if the universe is bad for sentient beings as you cannot gather data from the entire universe. These are all deeply theoretical opinions you've shared with no conclusion to be found. There is no closure and we don't understand lol. But the answer isn't destroy all life because you think you know better than the creatures deciding to live.

"most fundamentally whether one assumes positive value inherently exist
and is not infinitely less important than negative ones. Depending on
the axiology accepted it can be said that the universe is bad, good, or
neutral for sentient existence. For all of them or just the majority. If
we conclude it is a net negative for most of them, then it can be said
the existence of the universe is bad for sentient beings in general."

I did find this interesting, especially on a smaller scale than the entire universe, ultimately it leads me to the question of bias within value systems on ecosystems we don't even identify with due to disassociation from animal identity or misunderstanding intelligence as a natural permission for dominance. So how from an ethical stand point can nature be given a value like "net negative" in regards to suffering without asserting bias as a dominate species and without acknowledging the amount of suffering willfully created at the hands of humans, while labeling it as inherently bad in its own regard. I don't think we can math morals into nature, well we can, but i don't think its healthy or accurate.

I see your ideals in a sense and maybe the intent of this philosophy is to protect individuals from suffering and i respect that. But even as you stated less insects less suffering, the truth is less insects equals more death to animals that rely on them for food, and in turn those that rely on them. So less insects=more suffering until total extinction. But i doubt even with intentional extermination life will go extinct on this planet until the sun eats the atmosphere.