Because of this stupid drama that a vast majority of dota players don't know or care about? Or because people dump truckloads of money into Gabe's bank account every year for a battle pass they put nearly no development time into? Almost every feature is copy and pasted from years past and people still eat it up. The prize pool for a LAN that isn't even scheduled because of covid is at $20,000,000 (valve's cut being the other $60,000,000) and the funding period just hit the half way mark. Until you see the support start to dwindle i can't see it dying anytime soon.
Dota is one of those games most players never truly quit if you got pass the initial learning curve and weren't scooped up by LOL