How exactly was the 2000 version better? Sure, the product was hotter and had a more artistically pleasing main event love triangle, but it's not as consistent in the ring.
Hunter/Foley Royal Rumble 2000 alone is better than anything 1999 as a whole has to offer from an in ring standpoint.
Hunter/Foley NWO whilst not a GREAT Cell match, is still a lot better than you'd get from 1999.
Rock/HHH Backlash and Judgement Day 2000 were again far superior to anything Austin/Rock, Taker/Austin, Mankind/Rock could offer.
HHH/Jericho Fully Loaded LMS match is again on a whole different level to what 1999 produced.
Rock/Benoit whilst let down by the overbooked finish, was again far better than what Rock produced in his feuds in 1999.
HHH/Taka from Smackdown is a better TV match than I ever recall seeing from 1999 WWF.
The Too Cool/Angle & Edge/Christian 6 man from Judgement Day is fun as fuck and again, better than any 1999 opener I can recall.
The Dallas 10 man tag from February featuring HHH and the Radicalz v Foley, Rock & Too Cool is one of Raw's greatest matches, just an insanely great match/segment with an all time great crowd.
I'm not huge on Benoit/Jericho as a series (compared to others), but their series was better than any IC title match I recall from 1999.
Bear in mind I also ommitted the Dudleys/Hardys Table match from Royal Rumble, the Triangle Ladder match from Wrestlemania 16 and TLC 1 from Summerslam. All generally well received even if I have a pretty low opinion on the actual matches myself.
September-December of 2000 tbh is where the year gets weaker from an in ring standpoint, Angle/Rock No Mercy gets a ton of love but its been too long since I last watched it. Unforgiven and Survivor Series are largely weak, and Armageddon is equally disappointing (some love the 6 man HIAC but I'm no fan of it, more of a clusterfuck IMO).
But yeah, despite a weak period from September-December, the first 8 months of 2000 alone blow 1999 out of the water, christ January-May is in another league of its own in terms of match quality. Slowly but surely matches became more about the character performances, structure and story within a match rather than overbooked brawls (and even the overbooked brawls such as HHH/Rock Backlash was booked and executed more like Austin/Dude Love OTE 1998 than some of the poor 1999 brawls).