There is some impact on others, particularly those without ac.
Say a roof is absorbing 10000 watts. You install solar panels that absorb 2000 watts, used to power an airco. You now have your roof absorbing 8000 watts (released as heat) and ann airco absorbing (using) 2000 watts (also released as heat). Am I wrong? Seems like a conservation of energy problem. And you get a cooler roof so less airco demand too!
As a thought experiment, imagine you attach a heater to the solar panels (maybe it's a sunny day in winter). Do you get free energy for heat?
The reality is that a lot of old western europe was built for a climate that no longer exists. Houses are built to prioritize holding on to heat and rebuilding entire cities is definitely not possible if we're already bickering so much about adding heat pumps.
Yes, heat pumps may create a rise in temperatures in cities, but there are other things we can do as a society to also lower temperatures as to create a net-neutral impact.
And sure yes combined with other measures AC can be a net good.
If the roof was white and reflective then a lot more of that light would be reflected, but most roofing isn't.
Your logic isn't really compatible with the laws of thermodynamics.
Instead of generate heat you could say they move heat if you like, from inside to outside.