Core i7 7700K should be enough for all games today. Of course if you look at the CPU usage while gaming and you see it over 50% all the time, then yes, the 4 cores are not enough so it use the HT ones. Is this enough for you, or for what you wana see on the screen, it seems not.
If you ask me: "I have all the money in the world, What should I buy to be future proof (lets say 3~ 5 years)?. I would say go with atleast an 8 cores CPU with HT or SMT enable.
Is it necesary for today to get the best performance even in games that are not out yet, probably not really. A Ryzen 5 3600/X or a Core i7 9700/K should be able to get you there, atleast today and surely the next year too.
But it all depends, always, like everything in life, it all depends (in your case it depends on the resolution and refresh rate your aiming for).
Since you explainned, that you want to be able to play at 1440p@144Hz disaply and get close to that magical FPS number, you will need to pair that strong CPU (either Ryzen 7 3700X, Ryzen 9 3900X, or Core i9 9900K/KS - I would skip the Core i7 9th gen, since they don't come with HT) with a powerfull GPU, probably the one already suggested an RTX 2080TI.
Now, will this upgrade make every single game work flawlessly over the next 3 years or more, imposible to know. But for now, those are the main parts to get there.
Keep in mind, as mdd1963 worte, CPU and GPU are only two parts of a bigger ecosystem, Motherboard, Cooler, PSU, RAM and Storage are also important, and even if they only add a small percentage to the FPS counter, 1 weak link in the chain can make everything work like crap.