Well, if you wanted to match the glycemic load of a diet soda you would have to drink 100% less, i.e. not at all, not 'slightly less'. Drinking less sugary soda is not a comparable alternative to drinking diet soda, even if you prefer it. So saying diet sodas are pointless on that basis seems a bit non-sequitur. Also consider that 10% of the US population has type 2 diabetes, and almost 40% are prediabetic.
This is my life motto: eat well but portion wisely. I like butter. I like sugar. I like McDonalds, and cream, and cheese. So I eat these things, but only in moderation. I don't worry about trying to trick my tastebuds into thinking food tastes good. To me, artificial sweeteners taste bitter and wholly unpleasant. I would rather just drink water than drink diet soda. Indeed, I drink soda very rarely now, but once every few weeks a real coca cola is quite delicious.
Good point. I still struggle with myself not to eat the whole packet. I guess I've grown to enjoy the battle of wills and the sense of satisfaction of winning each time.
I switched from drinking exclusively sugar soda to exclusively sugar-free soda, and very quickly ended up preferring the taste of the latter. But I also discovered that non-sugar sweeteners feel a lot… lighter? They're easier to drink, simply put; my body knows it's not sugar somehow. I also have discovered I don't like the sugar rush, feeling on the teeth or aftertaste of a sugary soda.
But this is the whole difficulty about it. It's very hard to stick to a diet when there is so much temptation in the world. If you can have your aspartame cake and eat it, why wouldn't you?
Surely 40g of sugar if you do not need all that energy is worse than 0g of sugar.
Almost every advancement in dietary knowledge I have see over my life has indicated more and more that excess sugar (and carbs in general) is by far the biggest problem all over the world. And it is trivial to consume excess carbs with a modern lifestyle in a developed country.