<2% of input calories become beef calories. <4% of input protein becomes beef protein. Animal food products require an eye-watering amount more land than plant food products, even milk.
It is always more efficient to grow and eat plant protein directly like tofu. And even if it were true that you absorb fewer nutrients from something like tofu, then aren't you lucky, you get to eat more food.
While you are correct, you also have to consider the fact that cows are fed alfalfa, which is a crop that requires no fertilizer or pesticides and actually produces excess nitrogen fertilizer, which otherwise must be produced from natural gas. It also takes very little physical labor to harvest and store grasses and alfalfa compared to human food sources.
The only downside to alfalfa and feeding cows with it is the water usage, but for large parts of the country that aren't California and get decent rainfall, growing alfalfa takes no irrigation. You could maybe also consider the land area needed for it, but US cropland utilization has been dropping for decade after decade and isn't really a concern.
I eat alfalfa too, and sell some in my shop. But neither me or the cows eat only that: we like to diversify our intake to stay healthy and (global or local) logistic bring us a variety of other food/nutrients.
Sure some cows eat more alfalfa than me but most of them never taste a bit of that and only knows corn, soy and friends.
Some other superplants in the soy/quinoa category to consider: buckwheat and lupinus. Yummy.
https://ourworldindata.org/land-use-diets
It is always more efficient to grow and eat plant protein directly like tofu. And even if it were true that you absorb fewer nutrients from something like tofu, then aren't you lucky, you get to eat more food.