Consumer electronics use lead free solder, which has a higher melting point than the leaded solder you're probably using. For hot air removal I use 400-420 degrees F on 60% air flow with the big 858D nozzle, and small things like U9/U10 come off in 10ish seconds depending on how close you hold the nozzle.
For removing stuff like U9/U10 without hot air, the best way is to add heaps of your own solder to the legs until both sides have big blobs. Then you heat both sides by quickly swapping your iron between them until you can pull the chip off with tweesers. It shouldn't take too long to do that way, but you can keep trying until you get it with little risk. Unless it takes you more than a minute, then it's probably dead.
Lastly for solder joints, you want the minimum amount of solder to hold a good well heated joint. Your joints are visibly dull, lumpy, and stringy, which means your iron isn't hot enough/isn't heating the joint fully, and your tip is probably too big. Also, you're exposing way too much wire, you only need a few mm of exposed wire to tin. Exposing too much is bad practice and just asking for shorts.
Btw why are you soldering to those resistors? You don't need to connect anything there.