Comment by gridspy
Bear in mind that charging and discharging batteries has an efficiency penalty - perhaps 98% efficient for each. So 74 stored is worse than 72 used directly because 74 -> 72.52 stored -> 71.06 discharged.
And usually the efficiency is much worse than 98%.
Oh, and also batteries such as the tesla power wall can only be charged and discharged about 1000 times before they have lost a lot of capacity. So generating when you use also makes your batteries last much longer. You could think of this as a cost of battery depreciation per kWh stored.
That 1000 is for NMC batteries and its a 70% capacity. Still enough to be useful.
Also, there's a lot of factors that go into play. For example, this assumes the batteries are fully charged and discharged. If you do something smarter like going down to 40% and up to 80% then they end up being able to do a lot more cycles. In fact, battery age starts mattering more than the cycles.
But besides that, LFP batteries are currently being used in home battery storage (including powerwalls) because it's cheaper and it has 5000->10,000 cycles before dropping to 70% capacity.
Generally, though, I'd agree that having more generation throughout the day is better than having perfectly optimized generation.