That’s already the case at grid scale in more expensive markets like California. We’ve been supplementing night time power generation with batteries for years now.

Between 5 and 10pm yesterday, batteries supplied more than twice the power that our nuclear reactors did: https://www.caiso.com/todays-outlook/supply

The grid has become so expensive due to the cost of fire proofing infrastructure that residential installs are a no-brainer if you can find someone to do the install for a reasonable price. DIY is even cheaper.