Pretty common knowledge I thought, however welcome to the world of knowing that trash mice will actually make you trash at aiming
Mice are ridiculously important, well to the point where you really should not use a bad one if you want to be even halfway competitive and have a frustration-free time. A fair amount of general use mice (and even some "gaming" ones from the past) have prediction and/or acceleration built in, which ruins your ability to build muscle memory. Anything you can do to improve that will mean much better performance in game. You want to be able to move your hand and put your cursor in the same spot without having to actually consciously aim, something that can't be done with accel and prediction going on. As above, once you've got one that isn't terrible, you're good.
To tell you the truth Zefan, I've always understood that high grade mice were always better but I didn't know by how much when it comes to online first person shooters. I could never play Battlefield on this older system until more recently (x400 -> 980 TI ) but uninstalled by then so didn't get a chance to experience this mouse change. I've even had the opportunity to try chunky weighty mice and I hated them!
On the higher grade system I was always using the MX
I remember when I first was using the Razer Lancehead TE, the accuracy felt awesome but what got to me in the end was the weight. At 104g after a few hours I was suffering fatigue in my fingers and wrist. It could have been more to the fact it's quite a low profile mouse that I don't like claw gripping.
After that I jumped to the Steelseries Rival 310 from 2017 and have never looked back. Even to the extent I modified the Rival 310 down to 79g which felt even better.
Actually system performance matters more. Stable FPS even more so if you can smash 144fps and match up with a 144hz monitor. Most good FPS players will lower the DPI to 800/1000 anyway. So super high DPI is more of a gimmick than anything. Of course buying a crap off the shelf supermarket mouse won't be as good as a decent gaming one though.
I also remember getting used to 400dpi when Quake Champions was just released and it feeling like a brick. All these years later 400dpi feels fantastic with 1000Hz. I used to swear by 500Hz but 1000Hz feels so much better on a 240Hz display.
Even on the desktop I use 400dpi.
Then one day over a year ago after reading a lot of mouse aim techniques for aiming, I decided one day to try inverted. What a mind trip that was. 19 years of normal Y axis I felt like I was going to be sick.
Then stuck to it practicing each night in Quake Live and CS relearning muscle memory. It took maybe a total of 2 months to fully feel natural without thinking but it definitely improved my accuracy. That and the fact when I played flight games it was screwing me over with it being inverted at the time.
So now when I play any flight games, inverted feels natural in shooters and flight games. It took ages to learn it with a controller as well.
I'm always trying to improve my aim for sniper in The Division 2 and most of the time my accuracy is about the highest in the group through each mission. 62 - 75% accuracy with the most headshots. My accuracy only goes down usually in Legendary missions when there is a lot of cover hip fire spam since there can be 24+ npcs all firing towards you along with sniper dogs.
There has been many players thanking me in missions and shepherding endorsements for coming to their aid taking the aggro away from them as they get rushed to or close to their death while I'm sniping. Even those players dropping exotics/gear/weapons for my help.
I never thought I'd see the day where PVE in The Division can be just as hardcore as competitive PVP with speed run challenges and raids. Granted The Division also has small zone sections of PVP.
