Yeah at first, it sounds time consuming and annoying, but once you start excersing, you'll quickly realize that it is actually very rewarding. Makes you feel better ontop of all the health benefits.
Maybe this'll be a motivation for you. My brother was always slow at streaming, he didn't like playing maps above 190bpm at all because of it. He's been exercising/stretching very frequently for the past year, paid a lot of attention to having a healthy diet and gained over 10kg. He started playing Osu again just recently and suddenly he can stream up to 260bpm and it's still going up. His stamina is also really good. He personally credits this pretty much entirely to having exercised and having gained a lot of strength and flexbility from it.
Even if this doesn't convince you to exercise, at least pay more attention to having a healthy diet and maybe take a walk regularly, it's better than nothing. Whatever you'll be doing in life, you'll always have an advantage from having a healthier body, so you really can't go wrong with it (not to mention that you'll enjoy what you're doing more when you're healthy).
*Thought of this after writing, but if you're smart about your daily schedule, it is actually a lot less time consuming. You'll need to shower etc anyways, so you can always time your exercise with other activities to save time. An example. You need to go shopping and shower? Go running on your way to a store, buy stuff, walk back from the store, shower. Having a walk after running is quite good in itself, so walking home after running to the store is good, too. But yeah, you don't need to go to an extreme with this, it's only meant as an example, you can be creative with it, but if it's annoying for you to have to shower extra, just exercise before you want to shower, that would be the simplest way.