The Guardian has been receiving continuous buffs for a while, but I still think it's too weak for a rifle that costs 2400 credits. I play with the Guardian a lot, and the 2 main problems I've seen are:

1 - If you don't headshot the enemy on your first bullet (or second bullet, if the enemy isn't very skilled) you're pretty much dead, because in most cases the firerate is way too slow in order for you safely getting a kill by 3 hits to the chest, even at longer distances, where the Guardian is theoretically supposed to overpower the other weapons (except for sniper rifles)

2 - You can't afford to miss absolutely any shot at all because the recoil and spread are just insanely high, even for short to medium distances, and take a unreasonably long time to reset.

How to solve it? Reduce the firerate penalty while scoping (it's currently 19% instead of just 10%, like the other rifles), and make the recoil and spread a little bit more forgiving, at least the first 4 bullets should be accurate and then the recoil starts to kick in to punish players with bad aim.

If for some reason Riot don't think it would be balanced to buff the Guardian, I don't mind if they keep the weapon weak, as long as they reduce the price accordingly. The way it is now is basically a slightly buffed version of the Sheriff that costs 3 times more credits. Even though I like the weapon, I rarely use it on matches because it's very situational and way more expensive than it should be (if you can buy Guardian + Ghost, you can buy Vandal, which is definitely a safer option for almost all rounds)