Used a couple of US recipes recently and most of the ingredients are in cups, or spoons, not by weight. This is a nightmare to convert. Do Americans not own scales or something? What's the reason for measuring everything by volume?
Most baking doesn't require the precision of weighing. They are rough proportions, not an exact science.
An experienced baker, or really any kind of chef, will learn over time to make minor adjustments based on a lot of stuff. Maybe a bit less sugar, to taste. Maybe a difference in the brand or exact type of ingredient compared to what you're used to. Maybe it's a particularly dry day and you need to add more moisture to the dough.
If it's something I have a lot of experience with I don't even bother with measuring at all, just eyeball it.
I'm a trained chef working the trade for 30 years. 2 years in vocational school, a year for cooking and a year for bakery/patisserie. I'm a really confident cook - the concept of different cuisines, the basic ingredients and seasonings, no probs. Baking is still a rocket science for me. My current head chef said baking is fun if you know what you are doing but I'm still after 30 years not fully confident about the consistency.
I've heard that several times from different people... That chefs often don't like baking. Or are at least sceptical about their abilities (or the process.)
I think it comes down to the fact that cooking is active. You constantly season, add heat, remove heat, and check if it's done. Baking is more passive, you mix things and hope for the best, you can't just add more sugar or flour at the 10 minute mark.
My advice to anyone is start with pancakes. Make a few different recipes and pay attention to the differences. Then make them without a recipe. Switch up ingredients, sub in whatever you feel like, play with ratios. Once you have a handle on that, move to sourdough, cookies, or piecrust. Then do muffins. Leave cakes for last, because they are the most finicky. You'll be baking with confidence and without a recipe in no time.
Precise measurements are still helpful for learning. When I first started baking bread I had to measure by weight to get 60, 65, or 70% hydration, but at this point I can figure it out by look and feel, at least for the specific flours I'm familiar with.