MacOS in 2000 was still old MacOS, with no compositing at all. The NeXT derived version of MacOS was still in beta, and I tried it back then, it was very rough. Even once OSX shipped in 2001, it was still software composited. Quartz Extreme implemented GPU compositing in 10.2, which shipped in 2002.
Windows finally got a composited desktop in Vista, released in 2007. It was GPU accelerated from day one.
MacOS in 2000 was still old MacOS, with no compositing at all. The NeXT derived version of MacOS was still in beta, and I tried it back then, it was very rough. Even once OSX shipped in 2001, it was still software composited. Quartz Extreme implemented GPU compositing in 10.2, which shipped in 2002.
Windows finally got a composited desktop in Vista, released in 2007. It was GPU accelerated from day one.