Advanced batteries are necessary for mobile users of electricity (cars), but PV vehicles are nothing but a novelty. For most PV installations, if one is on the grid it is much cheaper and easier to just push power back into the grid. No battery necessary. Off-grid applications need energy storage, usually batteries, but these are a very small fraction of total PV installations. All of the people I know who have off-grid PV installations have some battery storage, and a fossil fuel generator to provide backup when it is most needed.
There is nothing inherently wrong with PV, but it is not cost-effective on an individual basis unless heavily subsidized by the government. Any real economist will tell you that this results in the taxpayer subsidizing the wealthy, but we all know that already.
Bloomberg tends to be more conservative on their projections than other sources. There are other credible sources out there who say this is going to roll out faster than what Bloomberg says.