The mushrooms in question have (roughly) 2.24g of protein per 100g[0]. Recommended daily protein for an adult man is 54g [1]. That leaves you needing to eat 2.4 kg of mushrooms every day just to achieve the protein requirements.

As a comparison, you can achieve the same protein with 450g of egg[2] or tofu[3], or 200g of beef[4].

[0] https://fdc.nal.usda.gov/fdc-app.html#/food-details/169242/n... [1] https://www.dietaryguidelines.gov/sites/default/files/2021-0... [2] https://fdc.nal.usda.gov/fdc-app.html#/food-details/748967/n... [3] https://fdc.nal.usda.gov/fdc-app.html#/food-details/174291/n... [4] https://fdc.nal.usda.gov/fdc-app.html#/food-details/746758/n...

You're comparing raw mushrooms to cooked, lean beef and appear to have cherry picked the lower protein common variety of tofu (instead of the higher protein calcium set variety which is equally common or much more common where I live).

If I use similarly misleading choices from the same dataset I could 'support' beef being lower protein than tofu by comparing cooked calcium set tofu to raw fatty mince. Or similarly, dried mushrooms would only require 600g or so (whilst also covering most of your energy needs).

At 4-6ish % by mass when cooked, mushrooms are decent, but not really higher than most plant sources.

Great source of many micronutrients though and complement tofu/beans well.