Was checking my steam account and I have an average of 10-20 hours in games that cost $40-60. These are games where I feel I got my money's worth. Games that I hate (but wanted to like) usually have maybe a little over 2 hours played.
If I have 750 hours into a game, that can mean nothing except that I really enjoyed my time enough to become obsessed with it, and the cost far exceeded the value. Now it's certainly a shame that you're leaving the game on a negative note (honestly I don't think you are actually leaving though), but really most players of Elite find it relatively easy to make ongoing progress (complete missions, defeat NPCs, fool the AI), even if the game is a bit grindy at times. Sounds like maybe you need an even easier game, not sure what game that would be tbh, since this one is near the bottom on the difficulty scale, and after 750 hours, you should know almost everything you need for basic flight and survival. Really that shouldn't take more than 50-250 hours, at most.
That's not to say that Elite is simple however, since I have over 3000 hours and I'm still learning new things.