Stronger than wood, in fact. A properly assembled glue joint will be the last thing to break on a wooden part. That reminds me that I should really get back to working on that desk I was building... months ago.
With the caveat that depending on grain orientation w.r.t. the joint, wood movement[1] can very significantly weaken some glued joints to a tiny fraction of their original strength, in a surprisingly short period of time. IIRC, Matthias Wandel (aka the Woodgears.ca guy) referenced above has a nice example of a poor joint vs. glue design in one of his videos, but I forget which one. :-/
[1] Primarily due to expansion and contraction due to changes in ambient humidity.