I'm going to take a very different stance to some posters in here. Cricket, sport really, is far more environmentally and era controlled than anyone admits. It is better for the narratives to focus on the people rather than the context they're playing in. Assuming relative parity in competitiveness between two sides, admitting even the very best of all time have less control over the result than the pitch isn't going to sell many seats or pay TV subscriptions.
The median bowler was less successful in the 2000s. No one debates what happened, but the why. One of two things happened - either 1) the entire world, outside of a few players, spontaneously forgot how to bowl despite all the advances and depth increases in world bowling for 30-40 years prior or 2) the environment dictated players who would have averaged 26-30 in 1995 now average 30-34.
It's #2. It's so obviously #2. It's inconvenient for some peoples childhoods including my own since Stephen Fleming (who averaged about 45 with the bat in the 00s) probably doesn't average 40 if he plays between 1985-1999, but it's #2.
The only argument that could be made against it is some of the greatest talents of all time like Shoiab and Bond were injured out of playing in the 2000s, and the dawn of biomechanics broke a fair few young players considered the future of their countries at the time like Richard Sherlock for NZ.
I would counter argue that the dry, flat and homogenised global conditions (the homogeneity being critical) meant batsmen had less to adapt to on tour and the conditions themselves dictated the era of the spinner, which the 2000s undoubtedly were. Long spells for game control became critical. Not just Murali and Warne, almost everyone had a contender for their best ever spin bowler during that era. South Africa and the Windies stand out as outliers.
With this context in mind, Steyn's achievements are more impressive since he bucked the trend. He was heavily assisted by spending most of his career on our way out of that era in the 2010s, but he did play on his fair share of CEO pitches. Ambrose still makes my top 5 all time though and I think he was the pinnacle of his era.