>>43753469>Red and BlueSeptember 28, 1998.
>YellowOctober 18, 1999.
>Gold and SilverOctober 15, 2000.
>Crystal July 30, 2001.
>Ruby and Sapphire March 19, 2003.
>FireRed and LeafGreenSeptember 9, 2004.
>EmeraldMay 1, 2005.
>Diamond and PearlApril 22, 2007.
>PlatinumMarch 22, 2009.
>HeartGold and SoulSilverMarch 14, 2010.
>Black and WhiteMarch 6, 2011.
>Black 2 and White 2October 7, 2012.
>X and YOctober 12, 2013.
>Omega Ruby and Alpha SapphireNovember 21, 2014.
>Sun and MoonNovember 18, 2016.
>UltraSun and UltraMoonNovember 17, 2017.
>Let's GO Pikachu & EeveeNovember 16, 2018.
>Sword and ShieldNovember 15, 2019.
>Sword and Shield DLC 1June 2020.
>Sword and Shield DLC 2November 2020.
Anon, they've been releasing yearly since 1998. The times they skip a year are an exception, not the rule.
Keep in mind this is still a small dev team. It's not that they're lazy or incompetent, it's that they're understaffed and overworked (and it's their fault.)