You saidOK. I mean, you're wrong. It's really that simple. Ukraine being in NATO actually makes things harder, not easier. You only need to look at two things to figure out why Finland is a major asset and Ukraine is actually a liability:
1. Carpathians
2. Murmansk
"I don't know why people still think Ukraine was somehow a lynchpin to a NATO invasion. The biggest threat to Russia vis à vis NATO wasn't Ukraine, it was Finland"
How the Carpathians in any way blocks an invasion of Russia from a Ukraine in NATO when it's at the other end of the country is beyond me

Carpathian Mountains - Wikipedia

Also as for Murmansk, yeah, it's important, a lot of assets there and in the region but once it's taken, then what. Because Kola. And as for assets, if you really wanted to, you can fuck that shit up with missiles, attacks from the American carriers, much easier than attacking through bog and scrub. Hunting for moose and collecting 10-42, best kind, attacking, not so much.

Kola Peninsula - Wikipedia

Then what, or to quote Dude where's my car... And Theeeen?
Whereas if NATO launches an attack from NATO you are closer to a lot more interesting stuff, serious population centers. Clear path to Moscow and Stalingrad [did I mention I am old as fuck]
Never mind that as WWII showed, the North is a pretty hard place to Advance, the Germans never made it anywhere near there, it's a pretty desolate place. OTOH The parts of Russia past Ukraine [as long as you don't go north into the Belarus and the marshes is pretty sweet for thrusting deep into the enemy rear.
So that would make you.... what's the word I am looking for, ah yes, wrong.
Now if you were talking about NATO on the defense, yes, Ukraine is a big open and vulnerable place whereas Finland is really defendable but considering how much trouble Russia is having with Ukraine, I doubt that's a worry.