That's a key qualifier though, energy we can extract.

I don't think energy recovery from sewage is feasible, not in the short term, not with our current infrastructure. But either way we should be treating our waste more deferentially in an attempt to recover the minerals 6 billion people poop every day. Except for water, everything in pee and poop is valuable if recovered (urea ->energy, phosphate ->mineral, sulphur ->mineral, starch ->energy)

Instead it all gets dumped to the oceans and the ocean dies from too much nutrients

I don’t think you are correct. A lot of places spread it on crop fields historically and many still do. It can be treated to remove (reduce?) the risk of disease transmission.

Animal manure is very good for plants and many gardeners seek out chicken, horse or cow manure.