I wouldn't do it. I achieve 100% on most of my Steam Achievements. Designing a game for the 14 people better than me would just be arrogance and would piss off the other 8 billion people on the planet. Nope, won't do it.

Most gamers are casual gamers, statistically. Design the game for yourself. If you get some vocal component of critics who feel your game is too easy, you'll also get some critics who feel it's too hard. You'll never win the battle of game balance. Just make the game you yourself want to play.

When the world outside your window is a fun and happy place, people want challenges. When there's a COVID pandemic, people want relaxing escapes. Keep the game at a level you yourself enjoy.

That being said, you can always have two difficulty levels, Normal and Hard. If it's a platform, you can easily make it hard by adjusting the controls. If I push the right arrow on normal, I move x+25, but if I move it on hard, I only move x+5, so it's much harder for me to dash and to dodge. Similarly, if I need to jump a gap, give the normal players lots of latitude on both sides but make it so the hard players have to time it perfectly or go splat.