Several years ago I built my own offgrid system as an experiment. It worked, but it took a lot of work monitoring everything, such as the batteries (lead acid). You can't overcharge nor undercharge them, or drain them too much, etc.
This Bluetti system is plug and play. Hook it up and start plugging everything in. I pretty much had everything but the house lights plugged in, balanced out so just as the batteries were getting low, the sun came up and recharged them back to 100% the next day. Rinse and repeat. You can monitor everything through both a Bluetooth or wifi app. I ran my washer and gas dryer, ceiling fans, home theater/TV, fridge, Kerig coffee maker, microwave, griddle, etc. Eventually I'll get a transfer switch so I can just use the house wiring instead of power cords.
I'm currently running an 8000 btu window air conditioner all day and night just on the AC500 with 3 B300s batteries. Works great if there is ever and extended blackout where the summer temps are 120 degrees in Vegas. Not kidding. People do die from excessive heat and I don't plan on being one of them. I did have to unplug other household things to allow 24/7 air conditioning. I imagine a more efficient A/C would do the trick.
One big advantage of this system over a DIY is you can take this with you in an RV, unlike a lot of systems you see on youtube, where they have a couple dozen 12v batteries lining a wall, heavy cables to the Inverter and charge controller, etc. Try bringing all that along in an RV.