fusions do need a range correction of some sort and back up plan removed from high impact. shotguns have had their range nerfed 2x. And snipers have never been what they should be in d2 dont kid yourself. the hardest to use weapon is actually the most gimped to keep kids like this playing the game or we wouldnt have the reticule bouncing when moving adsed or in air inaccuracy or flinch. all the weapons you mentioned have been touched. High impact fusions have not, however im grateful when the enemy team in comp is using them makes the win easier as long as you dont have someone who doesnt know how to bait their shots and use cover feeding them. They really are a drastically easier to use flinchless sniper that also can counter shotguns nicely that being said a good player with a sniper or shotgun will always get more kills and punish them.

Or maybe the fact snipers have max aim assist and insane bullet magnetism where you can shoot some one in their pinky toe and still get a headshot.

It's weird, but I think the complaints root from this issue. In Destiny 1, each primary weapon type had a specific special weapon that you just didn't want to contest. Autos did not want to fight Shotguns and Scout Rifles did not want to fight Sniper Rifles, but Fusion Rifles were so underused and had zero presence due to their projectile nature being crap in a P2P game that Handcannons and Pulse Rifles really didn't have that same treatment. It's different in Destiny 2 though; Fusion Rifles are now hitscan and literally dump on Handcannons and Pulse Rifles especially if the user precharges. I don't think people like that Handcannons and Pulses have a direct counter in the special weapon department after so many years of running rampant. They're not used to it and instead of adapting they just want Fusions nerfed out of the mid range entirely.