The point is that Big-"Tech" is not trying to get cheap electricity. If they wanted that, they'd invest in solar, wind and storage.
The point is that they know that the AI-bubble will burst, but they cannot admit it... as that would make the AI bubble burst immediately. After the burst they will need a lot less power as the profitable bits of it are a) just a small fraction, and b) tend to not need frontier models or huge data centers.
Now by "investing" in some questionable technology, like "SMRs" or other types of nuclear reactors, they can pretend that they invest in the future of AI, therefore pretend to believe that the bubble will not burst. In reality they typically have fairly small investments and perhaps some letter of intent to purchase power from them... should the project ever come to a point where it generates electrical power. Instead they are betting on those questionable companies failing so they can make a clean exit.
It's all signaling to investors.