Besides Lewis, Holyfield and Bowe it really wasn't. They were the standout fighters but below them the fighters were no different than the calibre around the 00's. Only difference is there are less Americans, therefore less US exposure, therefore the era must be ****ty.
If you took out the 3 top fighters of the 00's era like you did with the 90's the 90's would still be a better era. You had a faded, but still very good Tyson. Who was good enough to regain 2 titles and crush good fighters like Golota and Golota at his best was as good as some of Wlad or Vitali's better wins. Then you had Ibeabuchi who KO'ed a better version of Byrd than Povetkin beat and did it in far more convincing fashion. Tua himself was guaranteed top 10 material in this era and beat Ruiz far more convincingly than Haye. He was flawed but dangerous. Golota proved in his fights win Bowe, Ruiz and Byrd he was as good as some of the better fighters of the current era outside of Wlad and Vitali. I'd say he was better than Pulev, Jennings etc. Then throw in guys like Mercer, Moorer, Bruno etc and you have a strong era.
If you think today's era is ****ty that is your choice. It is my belief it isn't ****ty, nor is it as good as the 90's was.
Another reason it comes off as ****ty is tthat the singularly dominant guy is a guy who got hammered out by guys in the previous era. The 2nd most dominant guy of the era also lost to guys from the previous era. There was never a 3rd guy good enough to seriously challenge either of those guys. And there that there was never any chance that the top 2 guys would ever fight each other. Really it boils down to that there were never any marquee matchups. I guess we'll also need to see if the era is indeed actually over, if Fury can stick the fork in in the rematch.
The 90s was so strong, Holyfield couldn't find credible opponents to defend his title against. The 90s was so strong, the best prospect, Bowe, was upset a year into his title reign and quickly became a non factor and retired within 3 years. The 90s was so great, the oldest man in history won the lineal title from a former light heavy weight. The 90s was so great. Tyson served 5 years in prison and immediately unified major titles from the likes of Seldon and an aging Frank Bruno. The 90s was so great, a career sparring partner knocked out the fighter of the decade.
Some of your points are a bit moot. Holy defended his title against Bowe a man you just dubbed the best prospect of the 90's. Bowe lost his titles to Holy who is an ATG HW champion. Many people burn fast and bright. History being made is part of the greatness imo. Plus Foreman lost to a former LHW in Ali during the greatest era of history. Great champions making a comeback does nothing at all to diminish an era, especially if you are talking about Foreman being the lineal champion which renders talk of titles meaningless. Most eras have a big upset in them, especially before a champion hits his prime or as a champion nears the end of his prime. The only reason the 90's is so great is the level of fighters in the HW division during the decade.
The man had the top contenders avoiding him for 7 figure paydays and the HW lineal crown as prize. I believe it does attest his dominance pretty well.
Sums it all up If the fans recognise a name and know a certain fighter they tend to follow their career and every fight is an event and considered more than some other match ups against lesser known fighters, consequently people think they were tougher better eras. I have had similar discussions about other divisions