Here is a link to the tool that video uses. This isn't a case of someone compromising an existing smart bulb to do sketchy things, but rather someone installing this bulb covertly in your house and using it for penetration testing. the same could be accomplished by an arduino in the bushes or a guy with a white van out front.
Also most smart bulbs use zigbee or zwave not wifi. The hub could be hacked i guess, but I have mine setup to only be accessible on the local network.
The term "ratio'd" originated from twitter at a time when it had neither upvotes or downvotes (it refered to retweets vs comments). Fundamentally any platform that has more content than can be reasonably consumed by one person must have a way of filtering good and bad posts and as soon as you have that you have people who will chase both the good signal and the bad. You get rid of the upvotes and you encourage people comment farming, you see this on some platforms like tiktok where people will intentionally add in minor errors so that a lot of people comment corrections boosting their engagement or in traditional forums where every other comment is "bump". Personally I think upvotes are the least bad thing to have people fixate on as it has the least number of side effects.
I do agree that upvote begging like this post is parodying is bad though and should be discouraged.