I agree, which is why I was advocating for clean electricity to do the dredging.
The end of this article advocates for going back hand labor, which is what I was pushing back on as an unpractical return to a shitty past.
Hence, solar and wind power generating electricity, which are clean and green technologies but are not "low tech" do not fit his particular niche interest.
Though the article was from 2018. I think he may have evolved slightly as solar PV begins to feel more like a bit of lumber or a steel girder or anything else you can pick up at a hardware store and so passes his somewhat fuzzy and arbitrary definition of low tech.