Land usage is still lower

we show that plant-based replacements for each of the major animal categories in the United States (beef, pork, dairy, poultry, and eggs) can produce twofold to 20-fold more nutritionally similar food per unit cropland. Replacing all animal-based items with plant-based replacement diets can add enough food to feed 350 million additional people, more than the expected benefits of eliminating all supply chain food loss.

https://www.pnas.org/doi/abs/10.1073/pnas.1713820115

Complete proteins matter much less than you'd think. As long as you get the other proteins in at some point in the day you are fine. It doesn't take much for that as just adding rice to beans is enough to make it complete for instance

The bioavaliability of protein metrics are highly misleading when applying them to plant-based foods due to some their assumptions

While multiple strengths characterize the DIAAS, substantial limitations remain, many of which are accentuated in the context of a plant-based dietary pattern. Some of these limitations include a failure to translate differences in nitrogen-to-protein conversion factors between plant- and animal-based foods, limited representation of commonly consumed plant-based foods within the scoring framework, inadequate recognition of the increased digestibility of commonly consumed heat-treated and processed plant-based foods, its formulation centered on fast-growing animal models rather than humans, and a focus on individual isolated foods vs the food matrix. The DIAAS is also increasingly being used out of context where its application could produce erroneous results such as exercise settings. When investigating protein quality, particularly in a plant-based dietary context, the DIAAS should ideally be avoided.

https://link.springer.com/content/pdf/10.1007/s13668-020-00348-8.pdf