Your logic is very flawed, just because s1mple hasn't been bad doesn't mean that he deserved to be the best of the entirety of CSGO, he wasn't in top 20 for 2 full years of the game, how can you be considered the best of a game when you weren't even relevant for 2 entire years. If a new player comes out of nowhere and is godlike for 1 year he hasn't been bad at the game but can't be considered one of the best because the game has been out for 6 years...
Why does it matter that olofmeister is going down? If he started at his current level and was currently at his 2015 level he would still have performed the same for all of csgo, we are talking about all of the years of CSGO not how good he is currently. And although he's not as good as he was in 2015 its alot hard to get good stats or MVP awards nowadays because he's no longer in the star role of his team.
MVP titles : olof and s1mple are quite equal although olof has 1 major MVP
Achievements: olof wins by far (more titles, 2 major titles were as s1mple has 0) olof has made top 8 at every single major
Top 20 rankings: s1mple has been better the past 2 years but overall olof has made every single top 20 including a #1 spot
Relevance in CSGO: olof has been relevant and in the top for the entirety of CSGO were as s1mple started getting top results and performances in 2016, you can't be considered the best of the game when you weren't even around or relevant in the first half of its existence.