I never like Pick-10 because it was just furthering the unnecessary complexity of post-MW2 CoD games. Modern Warfare was pretty much perfect, but then latter games started adding multiple killstreaks, Pick-10, wildcards, customizable killstreaks, etc. And I get why being able to completely customize your playstyle is appealing, but I felt it lead to there being way too many variables to keep track of. For the past few releases, it felt like I was unable to prepare for a firefight because I had no way of knowing what another player was carrying. There are many games that do complexity well; Overwatch for example is a game with a multitude of characters, but if you see a Soldier 76 or Pharah you know what they're capable of. If you play Rainbow Six Siege you can look at an Ash or Thermite and know what to expect even though each characters loadout has flexibility. Battlefield has multiple classes, but you can reasonably guess what a medic or a sniper is packing. That hasn't existed in CoD for a while, so I rarely feel like I'm dying because I was outmatched but rather because my opponent had some loadout combination that took me by surprise. Pick-10 did have some advantages, such as the reduction in grenade spam. WWII is more restrictive in its class setups - and I wouldn't put the game on par with Modern Warfare - but here I at least feel on an even level with my opponents.
I know my opinion is in the minority though. It's totally cool if other people like it of course, I just never felt it was beneficial to how I played.