Mostly for monitoring so that you know how much your home consumes vs how much is directly available vs how much is in the battery subsystem accounting for inefficiencies, etc. and tells you realtime how many minutes, hours, etc. your system can provide power. I would also display how much energy is generated versus stored, time of day, etc.
That way you could play around with which devices are plugged or turned on when you lose power. Also, many gadgets still consume power even though they are “turned off.” It can be a significant amount of power. That probably means getting power strips for those devices — the good ol’ mechanical power switch.
With computations and knowing how much power you consume would be useful. Then you could better control the overall consumption.
Also, I have not tested this out (a disclaimer) but many devices that use AC and have a bridge front end and switcher back end will run off of DC. Example: your desktop PC. Obviously, AC motors or devices with an AC transformer won't work. Details to be worked out because the DC voltage has to be high enough for the switcher to turn on.
Yes, my inverter has an output through wi-fi. I don’t control it through wi-fi (to make changes I have to do it in person on the inverter’s control panel). But I can look at a current snapshot and have daily or monthly or even yearly graphs either on a website or a phone app. Plus it lets me download telemetry recorded at 5-minute candles that I import into a homemade SQL database service running on my laptop (I’m a data nerd by profession). I use the website for discussions with my wife in normal people lingo (hi, honey, do whatever you want whenever you want, but if you want to save a little money keep in mind that running the dryer on high temp drains power at 6 kW as seen here, while running...). I run SQL queries against the imported data for the geeking it out analysis I’ve been talking about in these posts. That’s how I know things like I average 2.44 hours per day in which my batteries are fully charged. LOL (to make me consider what to do with that power, like charge an EV)