Counter Strike has been the same game for 23 years, basically every new game is an “update”. Porting the game to Source 2 is the single biggest thing that has happened to Counter Strike since 2004 when they moved from GoldSrc, so might as well brand it as a new game.
Games have actually gotten cheaper over time adjusted for inflation even as production costs have risen, it’s crazy. A NES game in today’s money would be around $160.