Originally launched in 2012 and ported to the Switch in October 2019, Resident Evil 6 proved to be pretty divisive among fans of the series: many praised the game for its fluid combat and extensive Mercenaries mode, while others thought it strayed too far from the franchise's survival-horror roots.
Regardless, 1 million for the Switch version is a decent result, putting it about level with the PS4/Xbox One release of Resident Evil Revelations and roughly 140,000 copies shy of Resident Evil: Code Veronica on the Sega Dreamcast.
Sadly, Capcom has not released a wholly original Resident Evil on Switch, instead opting to port older entries in the series and creating 'Cloud Versions' of titles such as Resident Evil 2 and Resident Evil 7: Biohazard. Here's hoping we at least get native versions of these games when Nintendo launches its next major hardware.