Dead or dying trees, oak or otherwise, seldom produce much wood of useful quality for making stuff. You usually need to cut live wood to get good wood.

And there are many varieties of oak, some of which produce good wood and some that usually don't.

All of it burns pretty nicely.

Oak is a prefered firewood here, since there are lots of "scrub" stands. Unfortunately some of the suppliers have trouble telling scrub oak from Osage Orange (also common here), and mixing the two makes a nice hot fire - mostly somewhere other than in the fireplace when the O. O. explodes. (But it's only a little worse than green elm.)

John