Because:
- we do not need energy for private homes ONLY, we also need for industry, hospitals, schools, ... "buildings" that demand MUCH more energy than a home, similarly we do not need only private cars but also trucks, tractors, ... that demand MUCH more power not only in kW terms but also in load capacity and weight: a truck on lithium can be done in vehicle terms, but it's load capacity is less than a half and it's range is even worse;
- it degrade too quickly, without the blackout risk I would never ever put money on such expensive and little lasting batteries. P.v. can repay itself, battery can't and now due to high demand instead of lower they price they became also far more expensive.
Beside that even for my own small personal home and it's microgrid... Without the state/national grid I can't really run fully on battery/p.v. because when a significant load goes down, like my dishwasher have finished heating water (~2kW) and a small load goes down at the same time (let's say just a fridge compressor) my inverter cut the power due to high DC ripple or simply too high AC frequency. To avoid that I need a far bigger system (like 4 time the needed capacity in kWp) able to absorb the "overproduction" quickly enough or special tools (I do not know if they are even on the market) that climb and lower their loads softly to let inverters rump up or down as needed.
Oh, I'm talking about "state of art" Victron and Fronius inverters not some unknown brand from Alibaba... So far I've read claims that new (not available here, so far) Enphase microinvertes can be quick enough to reducing much such issues, while also cut the peak production, witch means that for x kWp you need x+1/4 panels kWp power since microinverters can sustain panel DC current but can't offer much more than a fraction of if on AC side.
It's not FUD, it's practically experimented state of things: with grid connected I lower around 50% my overall power consumption (more than 60% now and in summer, than less than 30% in winter, due to heat pumps to heat the home, especially at night and in early morning) from grid, without I can just survive blackout: some classic small UPSes for home rack and personal desktops, due to the aforementioned power cut due to microgrid stability issue, the rest on the battery inverter; when the Sun shine enough almost anything can run (at least, one/two high power appliances at a time eventually) and for the rest the battery and a small emergency generator to recharge do the rest, tested. It's environmental friendly? NO. It's cheap? Also no. I've done that just as a protection against skyrocketing prices and blackouts when I start thinking they'll came soon, and so far I was right, for prices at least, I've even need a slightly bigger plant for economical reasons, but that's all.
Did you imaging just a small restaurant with ~8-10kW mean power when open, with 15-20kW peaks? How much battery and p.v. it need? And for what? Can we even produce enough batteries for such small usages on scale? I can't answer myself but I've already seen comments from far more informed subjects like some CEOs of automotive sector who say absolutely no...
If you have other data I'm curious.
About EVs since you've cited Tesla: for my personal use-case an EV is still more expensive than an ICE ones, but might became on par or even cheaper when diesel will be, because I'm pretty sure it will, around 4€/liter (so far here is around 2€/l) BUT that's just because I do not need the car every day WFH, so I can charge it when the Sun shine, at least most of the time. Potentially with future (so far there are only some experiments) vehicle-to-loads I can use the EV as a secondary battery for the house, perhaps not fully charging it every day so to use it as energy dump to stabilize the microgrid lowering the TCO another small bit: how many people are in a similar situation or at least potentially they can? 10% of total population? What they can do those who happen to live a bit northern than here where p.v. is used but a bit of a joke combining average meteo + naturally low Sun exposure? How many have flowing water or constant enough wind to run on local domestic renewables? 5%?
I do not know if the TCO of a turbo-gas PP is higher than a p.v.+lithium ones, but I know a GPP can run 24/7 if there is gas for decades, a p.v.+lithium can't, at maximum it last 8 years or so for the storage part. And so far I do not know if we can even produce enough mega-batteries for such plants on scale. I do not even know if without turbogas we can keep a grid on, due to frequency perturbations and time needed to compensate. Windmills are relatively quick to adjust, hydro almost the same, p.v. definitively not. And only hydro is constant enough, p.v. can be just in few spot, wind in almost no place.