I counted calories and put everything on a scale, for about 2 or 3 months in 2022 (iirc). And you are 100% right. I had absolutely no idea how much calories some food has. There were a lot of things, but I think cashews were my biggest eye opener (probably obvious to a lot of people). I easily achieved my goal of -10kg and saved A LOT of money, because I always had food prepared. And since I was going for a calorie deficit, I easily could afford a few sweets on the weekend.

Then I obviously got lazy. And while I sometimes still think I can estimate how much I am eating, I am probably wrong, because my bathroom scale says something different. My key takeaway is that it takes quite a bit of effort, but once you got into a routine, it's not hard.

Edit: Also, while I might have tried to ditch "wasted calories", I didn't put too much effort in eating healthy. One step at a time.