No blue cheese dressing and ranch dressing does not taste the same.
At least in my opinion.
Ranch dressing tastes much better than blue cheese dressing.
Blue cheese dressing in my opinion tastes like vomit and is disgusting just like blue cheese is but some people love both blue cheese and blue cheese dressing.
Ranch dressing has a much better taste to it than blue cheese dressing although some blue cheese dressing has ranch dressing in it.
It depends on the type of blue cheese dressing you have but even the blue cheese dressing with ranch dressing in it doesn't taste very good to me.