Why exacatly did tristana need this change

She's the siege control ADC. She doesn't stat check people in the same way that Vayne or Kog'Maw does nor does she offer unrivaled amounts of utility (relative to other ADCs) like Ashe and Sivir do. Her niche is literally being just out of engage range while poking away at the enemy and being a damn bitch to catch.

It solidifies Tristana's identity as a reset-based adc. She already got rocket jump resets on kills. Now she can reset it more often, as long as she is attacking enemy champions. If she plays well, she can get a huge amount of damage from rocket jump, plus repositioning. If she plays poorly, she puts herself in melee range of champions that she should be kiting.

making the strongest ADC even stronger

trist is annoying enough as is, you can only get her in a teamfight by the third time you get to her. first time she will ult you, second time she will just jump away(or vice versa) then youll get her, UNLESS she gets an assist, you you have to get to her a 4th time

they buffed her combo and early game snowball potential, while nerfing her absurd late game a bit. I think as long as tristana gets good range late game, has a huge instant attack speed steroid, and a rocket jump reset...nothing else really matters. she will always be a late game beast. she's strong early, but let's not pretend that its easy to get a fully stacked E on someone. they basically have to be CC'd. and if you are CC'd by a thresh or blitz...any adc is going to kill you.

Because they removed the Extra dmg on w for 4 stacks on her e and removing the q cooldown reduction from e stacks.

They can't just take everything out of her kit without giving her some love atleast.