Tablespoons and tea spoons are fine as a measurement because they are made to a standard size. That’s like complaining people are using a piece of tape as a measurement. That’s what i grew up with, and it is what i am comfortable with. I’m not saying it’s better, I absolutely agree that variables in cooking such as elevation and ambient temperature/humidity matter way more and the overwhelming majority of the population wont notice a difference if you measure by volume, by weight, or are so experienced you just eyeball it.