Well yeah, obviously _infinite_ growth is not possible given the laws of physics.
But the whole premise of technology is that you can break the zero-sum and reach arbitrarily high levels.
For example Deuterium–tritium fusion runs on hydrogen that's pretty common to find. Yes, if we learn to exploit it, we will one day run out, but by then we'll have new sources of fuel. Similarly solar energy is just 'free' energy that rains down on our planet.
We could use that energy to farm fish or cultivate natural populations. We don't do that which is bad, but it's not some impossibility.
While you're not technically wrong, the idea of net-zero sources of energy does not address what happens when you start concentrating "free energy" in new places. Fish farms are ecologically monstrosities in most places they exist. Electricity is only one input, fresh water is another, and we haven't figured out where to get that much fresh water for free yet.
In many ways these arguments of "there's free energy from hydrogen fusion" feels similar to arguments about solving invasive species with another species because we haven't figured out that the new species will be invasive yet. And in a similar fashion, the local ecology may eventually re-balance (indeed, likely will) but what time scale are we looking at? Humans need human time scales.
But the whole premise of technology is that you can break the zero-sum and reach arbitrarily high levels.
For example Deuterium–tritium fusion runs on hydrogen that's pretty common to find. Yes, if we learn to exploit it, we will one day run out, but by then we'll have new sources of fuel. Similarly solar energy is just 'free' energy that rains down on our planet.
We could use that energy to farm fish or cultivate natural populations. We don't do that which is bad, but it's not some impossibility.