...and several classes heavier, more expensive, harder to disperse, harder to hide...

I (like a lot of people) don't see it adding up at the moment and are interested where they'll have to develop to add up again. I don't think that's even a particularly controversial opinion amongst experts?

Actually, (comparing an M1 vs an M2 Bradley), IFVs are often equal or larger than tanks. Israeli IFVs are often built from Merkava chassis (into Namer). And in this day and age of surveillance, both vehicles are easily spotted by UAVs etc.

Most experts actually believe that tanks are still valuable and that Russia's army is using them like idiots.

They are valuable - but some people with a well-informed opinion like myself, are interested in how valuable they are and how they're going to stay valuable as a core part of a division.