Like others are saying, your KDA is great, but your damage and kill participation aren't.
Your runes, masteries, and builds could be part of what's holding you back...
First of all, Attack Speed quints are about the same as 3 Attack Speed marks. This isn't true for Attack Damage marks and quints.
Let's compare gold values:
AS
Quint: 112.5 gold
3 Marks: 127.5 gold (13% better than a Quint)
AD
Quint: 78.75 gold
3 Marks: 99.75 gold (26% better than a Quint)
So, having 3 marks of AD is better than having 3 marks of AS. AS is better suited to Quints, since you lose less by putting them there. That's why everyone worth their salt takes AD Marks and AS Quints. You should do the same, unless you want to be cheesy and take a full AS rune page because it has so much more gold value. That can work, but you need to play a champion like Varus or Kog'Maw, who have onhit effects in their kit to help them last hit and trade with lane opponents.
The fact that you can manage to have a good KDA with your current setup is something to be celebrated for sure. It means you don't lose lane, but that doesn't mean you can't improve. I promise you your Tristana games would go far better if you had a proper rune setup.
What would also help you improve is improving your masteries. While some of your tank masteries are questionable (splitting points between Veteran's Scars and Runic Armor, and Legendary Armor and Swiftness?), your masteries for ad champions are generally okay. My recommendations would be: Try taking Dangerous Game instead of Bandit. Very few champions typically take Bandit outside of supports (Gangplank being one of them) and this is for good reason. You should, ideally, get 0 value out of the 1 bonus gold on missed cs. In an ideal scenario you should never miss a single creep, so you get minimal value out of that part of the passive. And as a ranged champion... you just don't get much gold out of hitting other champions. It would be better to have more combat effectiveness. (You seem to lose a lot of games at full build anyway... bonus gold isn't helping you win fights 40 minutes in when you'd already have all your items with or without 3 bonus gold onhit.)
My other recommendation would be to take Fervor of Battle every game on Tristana, as well as most ADCs not named Jhin, as it will help you deal far more damage in the lategame than Warlord's Bloodlust. While it stacks slower on ranged champions, you can counteract that by buying Runaan's Hurricane, because Fervor of Battle stacks onhit. In fact, it baffles me that you get Mallet on Tristana, but don't also get Runaan's Hurricane. You could apply the slow to multiple targets and be far more effective in teamfights.
Lastly, builds. Get Infinity Edge on ADCs. That's all. Please.
And if you get Runaans on your Tristana because of my earlier advice, you may want to replace Bloodthirster in your build with a Blade of the Ruined King.
You also seem to build the exact same items each game on Tristana, which makes me worry you follow the same cookie cutter build each game, rather than adapting to the current situation... which is something to work on if you want to climb. Try doing the math and figuring out the DPS of various builds in different situations, so you can get used to when different items are optimal. Use google spreadsheets. You'll thank yourself later.
Good luck, and always look to improve instead of passing the blame onto others.
