I guess you're not completely wrong then, but:

https://freestylersworld.com/showthr...ighlight=Lucky
Here is when it was added in 2012, read the post to see 11 Damage / 6 Clip / 800 Delay. It was like this for a while (we're speaking months/years) until the delay was increased to 900.

Limitbreaker has gone through plenty of balance changes in V7, as V7 lasted for 6 years, apparently not only affecting delay.

https://freestylersworld.com/showthr...e-nerfed/page2 thread from 2017 asking if Limitbreakers (11 dmg) should be nerfed to 10 dmg. That is post-V8 release though I must say.

Besides, your screenshot shows Limitbreaker with 10 dmg, 900 delay and 6 clips. You don't think +1 clip and -100 delay make a difference for the TTK (time to kill)? Think twice. All shotguns had lower delay in V7, and bigger clip size. Important difference.

Other than that I remember all the IA and R rooms in V7, where people would just spam shots until the enemy dies. As it is quite different now, of course it feels different and the TTK is increased with reduced damage, reduced clip size, increased delay and less spamming.