Worst case is pretty bad, and I don't think you can count on a best case. I can imagine a blowout with no warning. But don't take MY advice.
Consider doing this: Drive slowly to an honest professional tire shop that can evaluate in three dimensions (i.e., see how deep it is, and use their knowledge of the tire's construction) and ask their advice.
No big deal unless there’s any signs of the sidewall ply layers being involved underneath. If you can’t see them underneath that little flap and the tire is holding air, then everything is fine.
No big deal?
Are you really going to trust your life, and put other people’s lives at risk, based on users of an Internet forum looking at pic of your tire?
Totally reasonable to go to a tire shop and have them examine it. I suspect most will look under the flap and see if the sidewall ply is involved/damaged. If not, they will probably say it’s fine.
I have had much worse sidewall gouges from off roading examined at tire shops that would be happy to sell me a new tire say things are fine, and they are still fine many thousands of miles later including more off-roading and airing down. It all hinges on the inner layers of the tire being unaffected as I mentioned above.
To be clear, I’m not trying to say your tire is definitely fine just by this pic on the internet. We need to know if any deeper parts of the tire are compromised, which can usually be done with a quick visual inspection.
That video of the SUV blowing a tire is a great reminder of how a sudden blowout can cause you to lose control at high speeds. If you recall, Ford Exploders (Explorers) were having blowouts from not keeping their tires properly inflated; the exploders were rolling over killing people so the feds stepped in and mandated that all new vehicles will have Tire Pressure Monitoring Sensors (TPMS).
Sooooo, don't put yourself, your family, or others at risk, have the tire checked at a reputable tire shop. You might even get the opinion of a couple of shops if you don't trust the first opinion; there are definitely shops out there looking to take advantage of you.
I've run worse-looking tires since I spend time off road. I always dig into the cut and look for depth and any cords showing. The surface is not critical to the integrity of the tire.