I want to point out a few major issues with these calculations, and how to arrive at a more reasonable result.

First, 150 g of protein per day is a big amount, something that you could recommend to a 100 kg person who does a lot of sports (if you assume 1.5 * bodymass in kg rule, which would be a mid-range estimate). 70-100 g would be more fitting to the average person. Second, you make the calculation as if tofu was the only source of protein. Eg. Menno Henselman, a muscle growth researcher, has stated that our bodies are actually remarkably good at combining amino acids from different protein sources digested throughout the day. His recommendation is to increase protein intake by 10-20% if you swap animal proteins to plant proteins (note that the amounts in his presentation are for bodybuilders). A balanced diet would include a fair amount of grains, even vegetables and mushrooms that have protein. So all of this would bring the amount of protein required from the main protein sources way down.

Let's say that your main protein-rich foods would cover 70 percent of the total protein intake of a 100 g + 15% = 115 g (still quite a lot), that means 81 g of protein from tofu. With 14 g / 100g this would mean eating ~580 grams of tofu, or 145 g per meal over four meals, a very reasonable portion.

Now, in reality, I would not recommend eating just tofu as your main protein four times a day, but of course use some of the other great plant-based protein sources mentioned, like seeds, beans, lentils etc. Personally, I even throw in some sustainably fished local fish.