Here is a relevant 1:1 snippet from near the middle:
Nothing looks out of expectation here. You can definitely see the softness of the lens a bit, and it looks like the picture was overexposed. The lens sharpness for this detail with this size sensor is reasonable enough. The overexposure is making the tops of the flamingos look more white than pink.
The flamingos are brighter than the rest of the picture, but they are small. That may have fooled the auto-exposure system into underexposing the flamingos. You could have manually adjusted the exposure by -1, or your camera may have a mode where the auto-exposure system looks for small highlights and tries to not overexpose them. This is a tradeoff because in other scenes a few highlights may not be what you care about, and this setting would then waste dynamic range.
All in all, nothing looks really wrong here.
Note that due to the haze, the black level isn't black anymore by the time you get to the distance of the flamingos. You can't expect the camera to fix this, but this is something you can addressin post processing. For example:
Now the dark parts look blotchy, but that is because there was no detail there in the first place. Making them full black only makes this more obvious. If you do this starting from the raw image though, there will likely be detail in the dark areas so that you can make the darkest black and bring up the brightness quickly at the low end to show the detail.
Then again, a scenic picture like this isn't about individual flamingos anyway, so pixel peeping a small crop from the center like this is unfair. If you wanted a picture of the flamingos, you should have used the appropriate lens in the first place.