Not just good enough, they fit their niche almost perfectly.

Die often? Large passals that reach maturity relatively quickly. Have to risk ingesting potent toxins? Remember what almost killed you just long enough to get away from wherever it was(roughly 2 weeks). Not built for fighting? Fake your death so convincingly, vultures don't want to be near you. Nutrition might be scarce? Gather your feces, it will see you through.

Hell, even the fact that the Virginia Opossum can't adapt well to extreme heat or cold is a benefit to them, the resources they're driven to(such as actively running water, dense undergrowth for cover and foraging, and trees that can support their weight) can be scarce.

Maybe they just haven't had the chance for further education to get some wrinkles

Interestingly, it's looking more and more like evolution isn't random, and not only is evolution happy with "good enough", it seems like it actively stops there

Based on some recent experiments with bacteria and editing out existing genes, it seems like it chooses one genetic area at a time, and once it makes a marginal increase in an area it switches to another

It's possibly a mechanism to avoid a population boom then bust - if you improve too much too fast, you'll outcompete your environment to the point you destroy your own ecological niche

However it works (and figuring that out is bleeding edge research), it's very old. Interestingly, Darwin's later (unpublished) writings went in this direction, but the theories lost out to the random mutation theory

🎵My brain: highly developed olfactory processor

Your brain: anxiety possessor 🎶

We are not the same