I'm not gonna deny going against a full stack is super hard in this Crucible. However, if for you a 4-stack means you're gonna get 4v1'd the whole game that's on you for not adapting to how the game is now. PvP in this game is very reliant on teamplay, and if your team runs around lone-wolfing while the other team covers each other you're going to lose regardless of whether they're queued together. If you make an effort to stay around your team you should almost never end up alone against four people at once. If you make that effort, your team makes that effort, and you still get separated and stomped, it was probably half communication and half skill difference that won it for them. And there's not much Bungie can do about that beyond ruin the Crucible for friends who want to play together casually.