To forestall knee-jerk downvotes: I'm not saying climate change isn't real or that anthropogenic global warming doesn't exist. I'm saying the models are not yet developed enough to predict very accurately. Early heliocentric models made poor predictions too because they assumed circular rather than elliptical orbits, they were still more "right" than geocentric models.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...
https://www.theguardian.com/environment/climate-consensus-97...
The first link you posted is kind of punting on the hard part by saying that the reason the models overpredict warming is because CO2 didn't rise as much as they expected so if you put the actual observed CO2 concentration in then the temperature prediction comes out closer to what was observed. But the CO2 concentration is a parameter of the model, so they didn't capture its dynamics properly and then had to retroactively change it to get the observed data.
Again, I want to reiterate that I'm not disputing the process of climate change or saying it's not a problem. I'm saying that modeling it is hard and historically the models have overestimated warming.
I have tried a few times to find info on the accuracy of these models and couldn't find much. And most models seem to be closed source.