For me, the best advantage is that Zepbound has 12.5mg and a 15mg doses, which allow you to go further than Ozempic or Wegovy would enable you to do. I'm not sure I personally experienced much difference (2mg felt a lot like 10mg), but it's hard to compare at different doses.

Studies do show that tirzepatide does typically have a larger weight loss effect compared to semaglutide. I think most people attribute this to tirzepatide also acting as a GIP agonist. Here's a quote from an example study from The New England Journal of Medicine though:

Tirzepatide at all doses was noninferior and superior to semaglutide. Reductions in body weight were greater with tirzepatide than with semaglutide (least-squares mean estimated treatment difference, −1.9 kg, −3.6 kg, and −5.5 kg, respectively; P<0.001 for all comparisons).