That’s why it’s important to do some kind of testing to quantify the differences. If you can make a jump 9/10 times with one setting and 5/10 with another then you know which gives you better control.

Most important though is feel. Which settings are going to give movement the best feeling.

What do you want to do in a game studio? If you want to work in a big studio then they will be hiring people for very specific roles like graphics or level design. If you want to work in an indie studio then you would probably be doing a wider variety of stuff, for that kind of role your really want a portfolio of completed games so keep learning as you are but actually make and finish some small games.

I think it depends what kind of games you are wanting to make. If you want to work for triple A making the next God of War then yeah they aren’t using OpenGL. However, if you are interested in smaller indie games then OpenGL is still going to be used. I’m using OpenGL since my game is pixel art and would so the performance gain from Vulkan would mean nothing.

For stuff like this it’s a good idea to look at other games. Watch some Mario odyssey gameplay in slow motion and pay attention to little details like how fast the character accelerates and how much you can turn in the air. You should be able to create a bunch of variables like this for your game and then tweak them until it feels right. You can setup a really tricky platforming section and then see how easy it is with different settings. Come up with some profiles and have people play test to find what works for the average person.