A Wii U exclusive Breath of the Wild would have probably still beaten Halo 5 by a decent or good margin.

FIRST:

Second:

It's impressive to see Halo's brutal fall, 343I really did a terrible job with the IP.

Zelda and Uncharted 4 are also impressive, no one would have imagined that both would surpass Halo so unquestionably. Zelda and Uncharted never sold above 10M and, suddenly, they are doing +30M and +16M, crazy!

Unlikely. The best selling game on WiiU sold 8.5m and we know from Switch software sales that BOTW does not sell as well as Mario Kart 8.

Halo 5 sold 5m in 3 months, we got no update after that.

The WiiU was too much of a flop to support sales of BOTW to the extent that Zelda wouldn't have had the Incredible boost in popularity it has had if the game was shackled to that dead weight hardware. Delaying BOTW to their next console was the smartest decision they could have made.

Halo 5 was overshipped (exited the charts too soon), the final sell through figure is probably not much higher. Mario Kart 8's legs were cut short by MK8DX. This wouldn't happen to a Wii U exclusive BotW. Though I guess being released around Switch's time would have hurt its legs regardless.

At the time this thread was made, I think people expected a longer Wii U generation and a notably bigger final install base.

From what I remember Halo 5 never hitted 5M. MS stopped reporting numbers around that time. The most we had was it had a record opening with padding the numbers using the full price of the HW as if revenue for Halo.

https://gamingbolt.com/halo-5-sold-five-million-copies-in-three-months

Thank you, I just remembered that 460M opening not the 5M sales from a MS source.