" My dad asks me why I waste so much time in useless hobbies when I could be investing that time working towards next promotion and pay raise. "
I am never sure how to think about these people. It's probably great if you can find fulfillment in work and don't need other things to happy. But not too many people are wired that way.
Not that I sympathise much with the OP's father, but like most fathers he has the best intentions. In some cultures you can't waste your youth on frivolities, it's for building wealth to enjoy later. It works for some people and there is some merit in learning to defer happiness for periods of hard work, but you can't defer it forever. There is nothing wrong with relatively intense hobbies (the guitar can be very involving) but there is a good argument that an hour a day of practise is probably enough and securing a future needs to be done too.
My dad was like this - I got plenty of feedback, mainly due to laziness in my youth. However, once I got a job, he stopped advising me on my work or hobbies. I think in his eyes, if I managed to get a job making decent money and lived independently, I was old enough to make my own decisions.
I am never sure how to think about these people. It's probably great if you can find fulfillment in work and don't need other things to happy. But not too many people are wired that way.