Some other factors to consider:
3070s will require more rigs which increases the cost and makes more work to maintain them.
Older 4090s have a power issue with melting connectors, make sure the ones you're offered have the new connectors.
Thanks, JayDEe
If I say that I've never heard about this issue with RTX4090 I am lying, it is giving me concern too and I will like to know if there is a specific better connectors for this brand GPUs?
Also it seems that 3070 is better in terms of ROI but it will take even more space and extra effort on the maintenance too, but I still prefer the 4090 because it's minimal, in space-wise and other.
This is why I need information about the best power supply and cable connectors for the 4090s.
I appreciate all your replies Everyone, thank you.