In every day use in a phone however it's a waste of time and probably just taxes the phone far more than necessary for minimal difference to the end user experience.
Otherwise not so much. It just means the DPI goes into stupid territory and the phone OS ends up having to upscale apps to stop them looking like postage stamps.
It is a good thing that that doesn't actually happen and you are just spouting FUD isn't it?
It's not FUD, it's a realistic appreciation of the intractable problems that self drive cars are faced with and hardly likely to solve in an acceptable way in all circumstances. If you think that's FUD I suggest you look at the history of AI, speech recognition, handwriting recognition, robotics etc. and all the false promises made for those technologies and how far we have to go even today.
That's the problem and it's not just a case of "if you can't figure out these problems". The problems are intractable.
A more pertinent question is why is this being done at all. Are people so fat and lazy that they can't even drive a golf cart now?
A human can wave the pedestrian across the road at a junction - the self drive car will either sit there like an ass or plough through even if it's obvious to a human drive to yield.
If humans encounter a set of crossroad lights that are out they'll tend to order and arrange passage across the lights in an orderly fashion based on who arrive first and so on. If a cop is there, they'll obey the cop's signals. The autonomous car would just sit their like an ass or nudge out into the junction regardless of the consequences.
At the very least autonomous cars need an unimpaired human to extricate them from situations like this. This puts paid to some of the nonsense that people associate with self drive vehicles - no they're not going to drive somebody home who is asleep / drunk, no they're not going to park themselves down the road and come back when called. It's too easy for them to be confused and too easy for them to be griefed.
Not in the cases you mentioned earlier, high performance numerics and games. I've worked in both areas. To be fair I am assuming you are not including casual video games.
The general advice for writing games in Java is avoid creating temporary objects - use long lived objects, don't create objects in the scope of a loop, avoid for-each mechanisms (temporary iterators), reuse buffers and arrays, store as much state in values and buffers instead of objects and only release during transitions (game over, new level) etc.
Everything to reduce the duration and frequency of GCs in the middle of the action. Java GC works fine in general but it's very disruptive for the game world to freeze for a split second in a game because of it.
A right is not what someone gives you; it's what no one can take from you. -- Ramsey Clark