I've had this exact thought countless times as well, it's awful. People always blindly say it'll get better but it never does.
I remember especially back when I was a teenager people always blamed everything on age, "it's just your hormones" blah blah and apparently it'll all magically become better once you become an adult. As if lmfao, so fucking stupid.
I really hate all the meaningless phrases people throw around when someone is feeling suicidal. "It'll get better" like how the fuck would you know that?
Life doesn't come with a contract that has a guarantee written on it that states that everything will get better and bad things are only temporary (but as always humans just can't accept negativity). It baffles me people throw it around with such conviction, most of the time they don't even really know what's going on in your life to make you feel this way. Some people's lives are just unfortunate through and through.
I don't know your situation. but to me thinking your life will finally get better after years of suffering only for something to happen to throw you back into hell again was one of the most soul-crushing experiences I've had and I wouldn't wish it onto anyone. Letting you catch a glimmer of hope only to destroy it. It's fucking awful. Thinking back I'm pretty sure that was the thing that really cemented my suicidality.
Once again I don't know your exact situation, but I'm really sorry you feel this way.