Comparing Wii with Xbox is like comparing PS3 with Xbox 360. As a result of smart first party development given sufficient time, PS3 will yield better results than 360 but those conditions are usually not met, whether the time limitation or its not a 1st party developer, PS3 yields worse or equal performance.
Wii is certainly better than Xbox in most aspects; however its much easier to develop games for xbox due to its similarity with the PC artitecture and in terms of raw power, xbox might be slightly better due to graphics horse power. But when the wii architecture is utilized smartly, it will yield results clearly superior to Xbox. Though one should not expect something more than twice of wii or xbox at best case scenario! It would be too optimistic otherwise.
Playstation 5 vs XBox Series Market Share Estimates
Regional Analysis (only MS and Sony Consoles)
Europe => XB1 : 23-24 % vs PS4 : 76-77%
N. America => XB1 : 49-52% vs PS4 : 48-51%
Global => XB1 : 32-34% vs PS4 : 66-68%
