Not necessary is different from not useful. I don't think ANYTHING is necessary as long as your whole food nutrition is on point.
Useful is a different story.
There is no question that preworkouts are useful if your goal is to have the best workout you can possibly have. Find one person who takes a preworkout for the first time and doesn't say "holy shyt I had so much energy and felt so strong"
Even BCAA's which I highly doubt make much of a difference in anything, I started taking 5 grams before workouts combined with my pre-workout drink and I immediately noticed a positive impact. My in-workout recovery speed and resistance to lactic acid burn shot through the roof
None of these things are necessary though, you are right. Some would even argue that they do more harm than good in the long term because the body becomes reliant on them. I can't say I agree with that though, because you can cycle off of them.
As far as the answer to the initial question goes, any preworkout with caffeine will work just fine because in all of them, caffeine is the main thing that does the work. All the other ingredients are supplementary. I happen to enjoy Optimum Nutritions Platinum Pre because it has capsacin in it and there is a slight bit of heat when drinking it. Just a personal preference.
Never said they weren't useful, but I don't see the point of paying for freeform BCAAs when most wheys have them, most food has them, etc. and I don't enjoy those stimulants fukking with my head. If you have a nice light meal 45-1 hour before it works just as well for me.
I'm just cheaper than most when it comes to a lot of this shyt. Only thing I still pay for is whey, and yeah, you could say that's not necessary either, but it's useful for me because I don't have the patience to prepare and devour full meals sometimes.
Preworkouts are absolutely incredible as far as getting you focused and ready to go, but to me I didn't like the fact I felt dependent on them, it's $30 i'd rather spend on whey.
BSN AminoX tastes so damn good though
but yeah, although there are studies that say freeform BCAAs are more effective than BCAAs in food or whey, it's just something again, I'd rather spend on anything else.
If you got a shyt ton of money to spend on shyt, I think I'd honestly invest in a lot of these supplements again
cause i'm one of those people that enjoys trying new supplements just for the hell of it, but i'm stingy with a lot of that shyt now
I guess what it comes down to is it's important for someone to determine what's worth it to them or not