Honestly, European defense is pretty screwed if Ukraine falls.
this doesn't make much sense? it would mean europe has no defense. if you are european i wouldn't say that in public, you might get made into an example.
We'd be losing a million-man veteran force with the experience in the most modern warfare on the planet,
actual combat troops are estimated at 200-300k. a smallish portion of that are veterans, rest is constantly replenished (at a rate of 27k per month, per zelensky's own admission).
and instead Russia gaining their entire defense industry
ukranian defense industry is pretty much done already. europe has long not had any of note.
to turn all of that against other states in eastern Europe.
you wish. as things are going i would have not much problem with russia taking over decrepit europe. as a bonus you could keep using your own language (unlike, e.g., in present day ukraine). but i'm afraid russia isn't interested. if we go too far they will just nuke us.