You can't "count" protein in the same way that you can count carbohydrates or sugar or calories. This is because protein is much more complex and different types of protein vary in type of amino acids and your ability to digest it.
Thus quality of the protein varies significantly by it's source.
So 50 grams of protein from a hamburger is not equivalent to 50 grams of protein from a bean-based burger. Depending on the exact mixture of components and how it's prepared you might need to eat 250 grams of "fake meat" to match the 50 grams of beef protein.
Even in the USA most people don't meet minimum intake requirements for proteins. And it's very difficult for vegans to meet the minimal requirements.
It is possible, but it requires a mixture of different types of plant proteins to supplement each other and improve digestibility. But it's not a simple thing you can do by accident and very few people are aware of the disparities. You can even make things worse by mixing things badly.
I don't know all the details as I've only become recently aware of this stuff...
For gauging the quality of protein they have developed the DIAAS method to indicate protein quality. The old scale was PDCAAS, which some older dietary guidelines are based off of. However PDCAAS didn't take into account the digestibility of the protein, which lead to misleading suggestions.