why halo 2 legendary is not FIX on the Halo MCC

I PLAYED THE ORIGINAL HALO SO MANY TIMES NORMAL-HEROIC BUT LEGENDARY IS RIDICULUS BAD I ALL WAYS GET KILLED IN 1ST ROUND (SNIPER JACKAL -TRIIGER).

Going to close this off as it’s not a support topic. Halo 2 on legendary has always been very tough, if you are having trouble it might be worth looking up some walkthroughs on YouTube