And all of Elon's batteries at Hornsdale in South Australia will...

And all of Elon's batteries at Hornsdale in South Australia will need to be replaced before 2030.
Great for Elon.
Not great for South Australian electricity consumers who will foot the bill through high charges.
Not great for the environment, because Australia doesn't have the capacity to recycle that quantity of lithium batteries, let alone all the other lithium batteries that by 2036. CSIRO estimate that LIB waste generation in Australia will be 137k to 180k tonnes per year by 2036.
The largest LIB recycling facility in Australia is at Gisbourne in Victoria with a capacity of only 200 tonnes per year. There are other facilities too but no where near enough in total. I suspect that all those batteries that Elon installed will end up sitting in a toxic dump in one of the many warehouses that will be the home for Australia's LIB waste which the current Fed and State Govts have zero stratgey to solve.

Cue in a VRFB........the internal fliud will only need to be put through a cleaning cycle and then can be reused back into the battery.
I don't mind if it takes 5 years to build a large VRFB. The benefits outweigh the LIB problems.