Correct. It doesn't weigh the same as a cup of cream.
Nobody is claiming that American cup measures are measurements of weight. They are measurements of volume.
A cup of flour weighs just under five ounces, or approximately 127 grams. If a recipe calls for ten ounces or 300 grams of flour, you use two cups.
Basically, the recipe you use will come with all the right proportions of ingredients, which you measure by volume, not weight.
If you look on TikTok or the blogs of women with gel nails for your recipes of course you'll find all sorts of ungodly crap. If you look at sites like Food, Allrecipes, Bon Appetit, and a host of others, you'll find proper recipes for real food. Millions of great recipes, with huge numbers of reviews...
I don't see the recipes or blogs you refer to, because the algorithm brings me to sites that are not shite.