I have more than a couple qualms with using measuring cups and spoons…
Time-consuming: having to double check the amount, find the right cup or spoon, wash and dry it in the middle of cooking if measuring a new or different ingredient.
More dishes to wash: completely self-explanatory.
Creates dependency: Learning to eyeball ingredients and cook based on taste and personal preference allows you to branch out, experiment, and gives you a feel for the essence of a dish and how to substitute in a pinch. Following recipes and measurements to the letter leaves you unable to think outside the box and tied to a piece of paper or phone screen.
Causes major unnecessary mistakes: Did I add 4 cups of water or 5 already? Did I add 2 teaspoons of baking soda or 3 already? Oops, I misread 1/2 tsp garlic powder as 2 tbsp garlic powder, now the pasta is inedible. When eyeballing, you’re using your common sense to judge how much of an ingredient should go into the dish, and the more you cook, the sharper that common sense will become.
Prevents customization: One person may prefer things heavily-salted, another may be on a very low salt diet. One person may prefer meat-heavy dishes, another prefers to use meat in moderation and emphasize vegetables or grains. One person may be able to afford 2 lbs of shrimp, another may only be able to add a handful as a garnish. Someone might only have a few stalks of cilantro left in the fridge to use up, another might have entire bunches in their garden. One person may be able to tolerate extreme amounts of spice, another may want just a tiny sprinkle of cayenne. One person may love a ton of onion or garlic in their dish, another person might want to dial back the flavor. One person may like their soup very thin and brothy, another may prefer it thicker and closer to stew consistency. Make the dish about what you like and can eat, and what you have available, not about the numbers and measurements on a screen, and experiment!