Imagine if we started seriously investing in battery tech at the time the combustion car was invented and hadnt stopped since. We would still have been limited by not having computers for simulation for a long time, but we could probably have gotten to the current level like 20 years ago.
But yes, the future of electricity depends entirely on eco friendly, sustainable and cheap batteries. Its just a matter of time.
You could have totally built small scale water and wind power a few decades ago. Also solar was already viable 15 years ago and would have been cheap af if it had been scaled up to "economy of scale" levels. For example Germanies solar capacity was already at 1/5th of todays level 15 years ago. That was without any huge subsidies and the panels and feed in returns were not great either. We could have easily been at todays level in terms of solar 10-15 years ago if the lobby for it was as powerful as the coal/gas/nuclear lobby.