PS2 just eclipsed the rest by how insanely successful it was in nearly every way, its definitive proof nobody gives a crap about hardware specs when you have the best software output in the business. PS2 > Xbox > Dreamcast > GC but they were all good in their own ways.
Otherwise it feels tiny and uncomfortable. Also I'm in the camp that does not really care for the GC controller aside from some games like Sunshine or Melee working well with it. GC had a handful of great exclusives but everything else about it was a total afterthought and there was a pretty shocking amount of multi-plat games that even skipped the GC. Imo the Dreamcast wasn't even the weakest console of the gen, it was the GameCube. Its a totally different era I wish we could go back to. The library is staggering and very quickly after launch many amazing games were releasing at what felt like a weekly pace for like 5 years straight. Its the greatest console of all time imo.
The tag can be implemented in many ways, such as in between combos or utilizing special throws. At any point in the match, the player can hit a tag button to swap out with their other fighter, allowing the resting fighter to recover some lost health. Dreamcast is definitely a cooler piece of hardware in some ways and its sad that it died an early death but the PS2 was probably the perfect console for the perfect time. Continuing the fighting mechanics from Tekken 2 and 3, Tekken Tag Tournament sees players battling in teams of two characters. This was all because of Sega's incredibly stupid marketing of the Saturn, the PlayStation was so beloved that the hype for PS2 was going to kill the Dreamcast no matter what.
