Caution, yes. But most things in hardware come with varying degrees of risk. If you make a chair it could collapse. Clothes? Toxins. Electric car? Explosive.
Is the upside of "living in the future and building what's missing" not worth it though if you're cautious with the risk?
Unknown toxins in clothing is one thing. Building a device attached to your electrical wiring that likely violates the electrical code and puts firefighters as risk is something else entirely.
If those things don't disconnect when the power goes out and have a physical lockout for switch over to battery power they can easily kill someone working on the line.
Fortunately for linemen this risk isn't quite as high as it seems. If you are feeding power back power to the grid when it should be off your neighbors are likely to use enough power as to blow your local circuit breakers.
Do not use the above as an excuse to not have proper backfeed prevention on your system. It is a last resort that might save a life, but there is always the possibility that the isolated section is small enough that you can supply your neighbors without blowing any breakers.
That's assuming that your mains breaker is actually functioning, usually not too many of them get tested at 100-300A since the per-circuit ones trip first.
Last time I read up on backfeeding one of the common refrains was that flipping the main breaker on many homes still left one leg hot back to the transformer. Totally out of spec but common enough to be called out. Hence why a transfer switch is legally required if you're going to run your house from a generator/etc.
It isn't just the mains breaker. It is all the other breakers on your system. Your generators/inverter probably has a breaker someplace as well.
I don't know how common the one hot leg thing is. I know that can buy a lockout device which is just a metal device allowing either my main breaker or one other breaker to be on: thus turning my entire panel into a lockout. That implies the one hot leg thing isn't common but I honestly don't know.
This isn't plugging a generator into your house when the power's out. This is a system that's connected 24/7. That's difficult to do, requiring careful synchronization or isolation. Getting it wrong is probably harder than getting it right.
Is the upside of "living in the future and building what's missing" not worth it though if you're cautious with the risk?