Peace Walker is a fine game, but I wouldn't recommend it to someone new to MGS.
I finished MGS V main story for the first time last week. I played MGS 1, 2 and 3 as well as PW a while ago, and I was still confused by the story tapes, especially everything related to Zero because I never played MGS 4
. The references to The Boss, Big Boss, Liquid Snake and the Patriots
were nice, but MGS V is all about gameplay I think. I didn't remember who was Paz, just like her in the cutscene tbh
The story was just a thing for the fanbase to mull over, that couldn't even be finished properly due to Konami withdrawing their capital from the project before Kojima was truly satisfied, in order to invest in pachinko machines instead (and in some ways, it's a fitting meta-end to the MGS saga).
MGS V gameplay is a fine mix of MGS 3, MGS:PW, and Red Dead Redemption, I spent 100 hours on this game and I usually don't spend that many hours on a game since I became a wagie, I usually play short indie games like Pizza Tower.
I think it's fine for zoomers to begin with MGS V, and honestly after playing it, I wonder if the gameplay of MGS 2 and 3 aged that well.
My desert island video game would still be MGS: HD Collection or something like this, and I think every zoomer should play the PS2 MGS games to understand why Kojima is a big deal, but maybe it's more rewarding for a new gen gamer to experience MGS V first, and then to go back to the previous iterations of the series' game design and (much better) story telling if they like it.
It's kinda like philosophy books in a way: most philosophers refer to past philosophers, and while you can start with the Greeks, or Confucius, or ancient Indian spirituality, you could also start from more modern philosophers like Marx and then rewind the tape of history, till you find yourself reading older philosophers.
So I think OP could start with MGS V without any issue. It's normal if you are weirded out and don't understand everything at times, but after some point, if you want that stealth gameplay with good story telling, play MGS 2 and 3, they are classics. Then if you want the true background story, play Post too long. Click here to view the full text.