You'd be correct if the world's response to any military invasions over the last hundred years has been to move the offending country athletes' from international competitions. But that has not been the case, and the reaction of global institutions, including the global sports, to this war has been different from other wars. So no, this response could not have been predicted.
Are you seriously asking for examples of OTHER countries that invaded or destabilized other countries over the last few decades? Were you in a coma or just not into news?
You’re deliberately misstating the argument. No one is defending Russia’s actions. People are pointing out that the global institutional response is either completely new, or completely Russia-specific. That it is new is not incorrect. That it is Russia-specific remains to be seen.
You've just introduced two new annexes to the rules: a) the invader and the invaded have to share a border, and b) both have to be in Europe. Point a) is compulsory, point b) is strongly preferred but not compulsory.
Ah yes, it's all about member vs. Member.
I think you fully realize it's impossible to "outdebate" you here because you're obviously right

This move is unprecedented (Apartheid is nothing of the likes, and so is the withdrawal of specific teams).
However. The war itself and the reaction to it is kind of unprecedented as well. I don't recall UN being so unified over ANYTHING. And on the end of the day, we have a very clear aggressor who doesn't even pretend to have a casus belli (for one, they change the objectives and reasons every couple of days). So from the ethical POV this is kind of justified even if no one else has ever been banned.
And another HOWEVER, and here I'm being a bit frivolous with my interpretation of your point, this is not specifically anti-
Russian. It is anti obvious aggressor who had broken every single written and unwritten agreement and failed even to justify why. And I do believe, China would have been under similar pressure, at least in sport, had it invaded Taiwan; and I believe USA would have been too, had it invaded Mexico under similar expansionist imperialistic reasoning.
My proof is very simple. Russia has not been really sanctioned neither in 2014, nor in 2008, nor in the 90ies when it meddled in the affairs of every single of its ex-satellites creating such lovely places as Transistria, Abkhazia and Karabakh. Maybe it should have been, but it wasn't, despite giving every possible excuse. It took a full blown war with tanks (what is this, 1935?

), artillery on the cities and bombings from planes, after months of preparations, for the world to react in the severe way it did.
So personally I'm fine with it.