We as a species can do both without either slowing down the other — biotech researchers aren't the same skillset as politicians.
> If you have the wherewithall, ~100 years is more than enough time to get sick and tired of everything.
Disagree, that requires a personality which gets bored quickly. Expertise comes from having the passion stay for long enough to get really good — despite the meme this isn't exactly 10k hours, but it's still long enough that you can fail to grow sick of living after properly mastering just fifteen things in a century.
But even if you did, being ageless doesn't take away the opportunity to cease to be. If it's really all that dull, people will just take up extreme sports such as juggling honey badgers or naked skydiving over active volcanoes.