colors rendering very different in Library and Development v. export .jpg in sRGB

We absolutely need to know what application you're viewing the image outside of Lightroom. Lots of Window Applications are not color managed as D Fosse writes and that alone could be the issue. Doesn't matter if you export in sRGB or not, if that application isn't color managed, don't expect a match.

joannebusler  wrote On the left is a jpg that wan imported straight from my phone to my harddrive.

That's not the point. The point is what application you are using to view the file, and whether it is color managed or not.

Lightroom is color managed and uses your monitor profile to represent the file correctly on screen. Windows Photos (if that's what you're using) is not, and just passes the original RGB values to the screen uncorrected. A difference is expected.

However - a color managed display pipeline depends on a valid monitor profile, that is, one that correctly describes the display's actual, current behavior. A calibrator will give you that. If the monitor profile is defective or corrupt, Lightroom will also display incorrectly.

I can't say which is correct here. I agree that the version on the left looks more natural, so it's possible you have a bad monitor profile.