The OM1 sensor is stacked.But no one is doing that yet and I think it'll still be a while before it's profitable (by their estimate/margins) to do so across the board.... It seems Sony is happy with the volume of stacked sensors they can sell at 1" and at $6K on FF but not anywhere in between... Nikon and Canon only have a slightly lower threshold ($4K), and Fuji & Oly still ask about $2K for a body with a smaller stacked sensor.All sensors should now be stacked! m43, 25mp, aps-c, 30mp, FF std. 36mp and FF hr 60mp.
Not everyone is asking for this, a ton of shooters don't care about faster bursts, less rolling shutter distortion, silent shooting, or any computational implications from a faster reading sensor; they just don't. Personally speaking a faster reading sensor at a palatable price point would be the only thing that would instantly make me upgrade my A7R4, but I realize I'm probably in a small enthusiast minority.
A