Halo 5's REQ system isn't full-blown P2W, but it is a slippery slope. The fact that Warzone prevents players from calling in repeated high-level REQs over and over in rapid succession through generating REQ energy and hitting REQ levels means that advantages are generally temporary. Generally. Then there is the random aspect of it; there's no guarantee that spending money will get you all the good REQs, but statistically speaking it does increase your probability when you supplement REQs obtained through playing with real life money. Then someone whose dropped $100 on gold packs has a greater chance of having many copies of good REQs compared to the average player, meaning they'll be less inclined to save their good REQs when playing and more likely to call those REQs in during play, since they'll be less worried about running out.Not entirely true. In Warzone turbo players are allowed infinite energy and are allowed to spam as many REQ's as they want. The only difference in normal Warzone is it's just slower but the fact is it's P2W model, is technically gambling too but the point is no matter how 'lucky' someone is...the game still caters in those modes to whoever has the most REQ's.
The closest Halo 5 has gotten to P2W was with the introduction of the Mythic REQ Packs that let people spend $10 for guaranteed copies of a specific high-level REQ, like Nornfang or the Gavel. That removed all chance from the equation and gave players an opportunity to use real money to stock up on some of the most powerful weapons in the game. That was a terrible move by 343i/Microsoft/whoever decided to do it.
Example: 1 team doesn't have plasma pistols then another another has plenty of tanks then the one paying to have an endless supply of tanks will surely win unless the players are extremely bad at the game.
The point is no matter what happens...if the items given is high/low REQ tier item's then that player has a near infinite supply of them to spam then they have a tactical advantage over anyone who is trying to play the game who either has started or trying to earn them...so it's still P2W. If someone has a lot money to waste on packs then it won't even matter what the chances of someone has of unlocking a specific item because the player would get it eventually regardless because there chance's would have increased based on much money they have wasted. Anyway gambling in loot box's is just as irritating as spending micro-transactions.
Aside from your points about WZT, you basically said everything I said and just called it full-blown P2W, where I called it a slippery slope. I'll grant you that Turbo combined with the availability of Mythic REQ Packs for $$ is pretty much full-blown P2W in Halo 5; you spend as much money as you want for guaranteed copies of 1-hit-kill weapon in a game mode that doesn't at all restrict their use. Normal WZ, not so much. Here's and example of what full-blown P2W is in my mind: "buy this gun attachment that grants you 2x accuracy/damage for $2.99!" or "spend $10 and become invisible to enemy radar!" and there is no other way to get those buffs other than buying them. No random chance, no game mechanics that prevent/limit the use of things that may have been
attained through dropping cash; true P2W is just there, all the time, and only through microtransactions. There are models that approach this to varying degrees, like Halo 5, but I wouldn't call those models true P2W. Doesn't mean I support such models that approach P2W, but I also recognize that, like everything, microtransactions exist on a spectrum.