Not really, everybody has known that tanks on their own, unsupported by infantry are incredibly vulnerable to anti-tank missiles since, at least the Yom Kippur War (50 years ago) probably longer. The Russians for various reasons didn't and the results were predictable. So no MBTs aren't obsolete they just are very easy to break if you use them wrong.

Also there are newer active protection systems that can defeat missiles like the ones being used, the Russian tanks in the invasion either don't have them or don't have the ones that can detect threats from above.