HDR is in its simplest form blending where the pixels are weighted by their distance from the middle value. Blending is more like a constant weight or other function based on blending mode. In your example you are not really gaining much extra DR in the outside area. Your HDR does recover teh details but have a flat look because of the boring tonemapping that needs to be done to map the floating point image back to 8bit. It looks like my technical images where I just apply a gamma curve and nothing else.
Remember your original 2 exposures already used your dynamic range in 8 bits, and now you squeeze these together. Make sure you get the result back in 16bits so you can control the tone mapping. Adjust gamma, curves, and saturation. you especially want to split process the saturation so teh darks get desaturated more than the bright areas.
HEre I did a bit of tweaking on your 8 bit HDR image:
For kicks I copied your two exposures into image view plus more to see how my own algorithm looks. I dont remember if I activated a color tone mapping based on human perception experiments I found in a research paper in the code at this moment, though. Id think yes, as the colours out of the box resemble more the colours if my tweaked version of yours, except for the dark areas and the green.