Funding is essentially step 2 to becoming an esport. 1) build the competitive community and get stand out players 2) tournaments and leagues. This is where the money part comes in, yeah you could do leagues and ladders with no prizes but you're not moving the community forward towards becoming an esport. 3) streaming and promoting. Now that your community has a funded league and you're starting to separate amateurs from pros you want to bring in cash flow to support the league. Streaming, merchandising, and registration costs are going to be your big 3. 4) more online leagues and LAN events backed with cash prizes and big name players. 5) do everything I just said in larger scale as the scene grows. 6) franchise, not only the game but the teams and players
Yeah it comes "later" but is a huge step in making a game successful competitively. I can give examples from games who lose funding and it destroys there competitive scene.