its because the current fotms arent as good as some fotms before. You cant solo forge like before because bandwith, you cant swarm launcher like be4 from roof because range. You can't kill as many mlt scrubbers because apex and more squads in more matches. Overall awareness went down hard with all the scanning nerfs, and scouts have cloaks, instakill any suit proto knives with 2.5m range and a almost 180-¦ hit box arc, and bons uber shotguns.
And perhaps most of all, jump mods mean virtually every assault is no longer stacking regular armor plates, thus all of them blueshield super hard, especially if you use a RR(if ya dont got officer,calass, or calmando put the garbage rr away).

Combine that with commandos, nade spam, assault hmgs, officer spam, todays horrible map pool, and you get that people who havent adapted to the new fotms that they like, will always do worse. You could also be soloing now compared to squading before, your sensitivity settings couldve been reset or just be high where they shouldve always been low.