The grants (including VC funding, which might eventually disappear under a Bitcoin Standard) are used to fund the "big jump" versions, where they move quickly from an idea or simple PoC to a completely revamped and fleshed-out version. Then they are weaned off of the grants or the grants are reduced, and they attempt to quickly match the missing funds with fees, to cover running costs.
There is currently no universally-viable concept for fully returning the costs Big Jumps incurr.