The most endangered from human activity is all life. There is a massive die off happening and will only get larger impacting all plants and animals.

But you're right, the planet will still be here once we're (and everything else) is gone.

The most endangered being from human activity is humans.

We're not just making the planet unlivable for us. We managed to get rid of almost half of all the insects in the last 30 years. We made countless species go extinct via various methods. And that's just a few of our "achievements".

I get what you’re saying, but I think memes like this are trying to do a few things:

• frame mankind’s unique ability to think beyond just the interest of self to drive a sense of common purpose (i.e., increase our chance of survival and avoid self destruction).
• to that end, evoking the construct of a helpless and fragile planet as the calling to fight for self preservation as a species probably works better since all signs point to our inability to act on behalf of a greater good for mankind.
• the imagery and framing of this sort provides subliminal messaging that we collectively and individually have a power to do something about it (humans can create the problem as well as the solution). Honestly, even if it weren’t true, it feels better to think we can affect change rather than not.

Well, if you frame the issue as humanity being imperiled, you kinda lose the misanthropic and psychopathic crowd, which is a significant percentage of the population. They might uh, hear that news and go: "Great! Population Zero, here we come!"

Whereas, the planet being unlivable, means they die too.

It's all about psychological framing.

Some people simply can't be compelled to care about anything except themselves (and nearest family / friend circle / insert object here). That's partially how we ended up in this mess in the first place: The Tragedy of the Commons.

Sorry to put it this way.

And I soft hate 'the planet will be fine' people.

It's figurative, not to be taken literally. This is not difficult. You're trying too hard.