This being said, Russia also isn't as weak as we like to think. Given how the war has ground to a standstill, it's not unlikely it'll become yet another frozen conflict. And that's after arming the Ukrainians with large amounts of advanced weaponry.
We've become so used to the idea we'd have air supremacy in any potential war, we thought the Ukrainians would be able to push their way through the front, forgetting that the Ukrainians aren't able to take out artillery or mines beforehand.
The Russians have also adapted quite quickly. At the beginning of the war, the Ukrainians were having huge successes with drones. Now the Russians are downing 10,000 drones a month:
To be clear, Russia is an existential threat to Europe. If they turn this conflict into a stalemate, they will have won territory that doesn't belong to them and it's almost certain they'll rebuild, rearm and do it again. Just like happened with Moldova, Georgia, and Ukraine in 2014.
But underestimating the Russians is not in NATO members' interests. No one ever won a war underestimating the enemy, better to give Ukraine more than they need, than just barely enough to make incremental advances under the assumption Russia won't do a second wave of conscription and/or doesn't have (or isn't building up) reserves for a (counter) counter-offensive.
And given how Ukraine has struggled, even with advanced weaponry, it's clearly high time for Europe to re-arm so that Russia doesn't mistakenly think we're weak.