Water damage, iPhone 11 Black screen still Responsive

iPhone 11 bought in March 2020 from Apple, limited warranty- Probably did so many things wrong, didn't realise it would reach this extent until it was too late, didn't read any of what you should do after coming into contact with water until too late either.

-Current condition: Black screen, will not display anything no matter what, still responsive to touch and will charge (it makes the accompanying noises/vibrations and an alarm went off which I stopped by touching usual spot)

-Previously had an iPhone 7+ that had been submerged in pool water on multiple occasions for various times and it works perfectly

-Googled if newer phone was water-proof yesterday came up with the 2 meters/30 minutes resistance

-Submerged it for no more that 10 secs 2 inches underwater- did this 3 times

-May have been splashed close by?

-Sat it on a table for a good hour

-Picked up and noticed slight screen glitch- scrolling through photos too fast would cause tiny tiny grey grid to cover entire screen

-Over the next 2-3 hours, proceeded to use phone as per usual, restarting periodically and playing a YouTube sound clip to vibrate water out of speakers

-Screen glitched more and more often with use

-Plugged in charger and got the water notification, unplugged but re-plugged not to long after, force restart

-Darker patch, “oil” spill-like appeared in bottom left corner

-Stopped working entirely, current condition as above