A lot of the recipes that I've seen on YouTube and different forums have used four main ingredients when making pizza dough - flour, water, yeast, and salt. I'm confused because I though sugar is also a main ingredient since yeast feeds on it. Would y'all recommend always adding sugar to the pizza dough recipe? Also, what if the flour that's being used already has a few grams of sugar - should I still add sugar to the list of ingredients?
Sugar helps the dough rise faster, and increases browning. So using it is a matter of taste, and what you like in a pizza. If you're in for a day-long rise in the refrigerator (for example), you won't need any extra sugar. If you want it faster (say, an hour rise in a warm proofing box), a little extra sugar can help.
If you're happy with the way your pizza browns, leave it out. Extra sugar could even cause it to burn, especially if you're using very high heat. If you feel like your pizza could use an extra pinch of Maillardy goodness, add a little sugar (and be prepared for a shift in rising times).
The sugar is not for the yeast. It is for adding browning in a home oven that cannot reach the 600-900 degrees of commercial ovens.
For example, in this Peter Reinhart's Neo Neapolitan pizza recipe he advises to use a tablespoon of sugar to make four 10oz dough balls. https://www.bakepedia.com/peter-reinharts-neo-neopolitan-pizza-dough/ If I recall correctly, most of his recipes in his American Pie include 1 or 2 tablespoons of sugar.
The Enzyme Amylase helps break down flour starches into complex sugars that add to crust color, taste of the final produce and feed the yeast to produce Carbon Dioxide (bubbles). Slow rise gives the enzymes time to do their jobs. A quick discription