We should not expect their first iteration to accurately model clouds, but at least they are factoring it in now. How much did consensus override the concerns about cloud cover during the formation of climate models over the last few decades? Consensus is just a fancy word for groupthink.
We should be asking how much more accurate do our models need to be in order to predict future climate?
There are cycles such as the Atlantic Multi-decadal Oscillation that we still don't really know how to model with a high degree of accuracy. The AMO has dramatic effects on climate. So does the PDO.
We don't know how volcanic activity is going to play out over the 21st century.
We don't know how much cosmic ray flux will increase if we enter a prolonged solar minimum cycle like the Maunder Minimum.
There are a ton of factors that influence climate that our models don't account for.
https://www.geosci-model-dev.net/10/2247/2017/
> We compare the climatic effects of the CMIP6 solar forcing dataset to its CMIP5 predecessor by using time-slice experiments of two chemistry–climate models and a reference radiative transfer model... This solar-cycle response is slightly larger, but not statistically significantly different from that for the CMIP5 forcing dataset.
We may not know the exact values of cosmic ray, volcanic, etc. inputs into the systems, but we can make reasonable conclusions about their high and low end values and the likely impacts that result. A quick Googling will reveal plenty of research on (and mentions in IPCC reports) the things you assert are being ignored.
No science really ever is.
The problem you run into, though, is that people who don't understand science confuse "we're continuing to refine our knowledge" with "we were completely and totally incorrect".
Discovering clouds play more of a role than expected is useful information, but it's a far cry from shaking the consensus on climate change as a whole.