A store going solely online is something that is off in the future. You can still buy from certain companies but I wouldn't say it is better than going out shopping. If my local grocery ever went just online ordering. They would be in for a rude wakening sense most people would see it as more a inconvenience. Then something that is with ease of access that would allow you to purchase without waiting in line. You still have to wait for the item to be prepped and shipped which takes at least a day.
I never prefer to buy anything online, especially when it comes to clothes and groceries. I would go to a store near my house and buy everything from there instead of shopping online. I have realized that quality is never good when you shop something online no matter what it is.
I use this service somewhat regularly. In my area, it is only the two nicest (and independent) grocery stores who do it. You pay a small fee (which can be one time, monthly, or yearly) and do all your shopping on the computer. Then you pick up at the store, but you can stay in your car. You can pay with cash or credit card, and you can even use coupons. This service has saved me TONS OF TIME and money. I love it. I find that the small fee actually pays for itself in the time I save. I like shopping in a grocery store, honestly, but it gets tedious when I have to drag all my kids along. If I ever go back to work full time, I plan to subscribe yearly and simply make this my new habit.
I have done grocery shopping online before. Actually I lived in San Jose, CA, close to where you are and there are many options for online grocery! My favorites were Walmart and Safeway, they deliver exactly what you asked, if they don't have it in stock they'll automatically pick something similar for you and if the value is higher they'll charge you the value the original product you asked for was, and if you don't want something they'll bring it back with them and not charge. It's a great way of shopping!