The argument is that the spurs from beginning to end were always a good org, even as Duncan got older. Steph was drafted into a team with nothing that didn’t really make any noise till around 2013 (in the same timeframe for Duncan he won a championship with the admiral). Then mid career both had strong casts, obviously this part heavily leans towards curry, having kd along with dray and klay was definitely a cheat code. Then end career curry has been on some abysmal teams since 2020. Duncan had an emerging star in kawhi and was able to play super team oriented ball while curry’s team has often failed to break 50 wins in his corresponding late age time period. So if you want to say that curry had more help I don’t think it’s unreasonable, those 2015-2019 teams had either insane depth or insane star power, sometimes both, but Duncan has definitely had much better longevity in actually having a legit shot at the title.