Don't get upset Gracem, you are doing the best possible thing you can for your children, as most people on this site are, and we have different opinions about what is best.
There is no such thing as a dead end school, honestly there isn't! And there are any factors that affect how a child does in school, the actual school they go to is quite far down on the list.
The top factors are
a) intelligence
b) parental support
c) peer group
None of us can do anything about A! But clearly yours have B and you ahve done what you can to get a good C, in that they are largely mixing with others who have B
My DC go to a school 2.5 miles away too, we don't consider it far, and they do go by bus or walk, but this is at secondary level, so a bit different.
I suspect your children will reach their potential whatever school they go to.
For what it is worth, as a teacher of several decades standing, I have come to the conclusion that it is hard to go wrong if yu are trying hard to do what is right for your children, because the fact that you are trying to make the best decisions in the end affects them more than the actual decisions themselves.