Well, for console players, an Xbox was the only way to play Counter Strike (which didn't release until years later and may not have been a priority without Halo's popularity), and Unreal Tournament came out in 2000 on PS2 and 2001 on Dreamcast, and those ports were pretty bad. What Halo did was bring the FPS experience to a controller, not just a console. Before that it was hit and miss with controllers and FPS games. Halo is where the layout really locked in.

What matters even more is Halo 2 bringing things like matchmaking, parties, and playlists to FPS games. Without that, consoles would still be stuck on server lists. Would all of those innovations have happened without Halo? Would CoD and Battlefield be where they are now without Halo? Probably. But Halo is what brought them up.

And you say that the 360 was where console online gaming really came into it, but Xbox Live on the original Xbox was amazing. Voice comms while playing Ghost Recon. MechAssault. Rainbow Six 3. The Dreamcast tried, but it never made the leap. The Xbox and the Halo series are what pushed consoles into a closer parity with PC gaming, and you can see how true it is just by looking at the offerings that Sony and Nintendo have made. Sony has caught up now, but it took them years longer to follow Microsoft's blueprint, and Nintendo still hasn't figured out how to do proper online gaming.

If it isn't for you, it isn't for you, and that's fine. However, calling it over-rated and crappy is a pretty hot take. That's like booting up DOOM and saying, "Why bother, we already have Wolfenstein."