Is 1500 really hard to get in blitz?
That is a subjective question. For someone it could take alot of work, another guy gets it quickly by just playing blitz.
With regular training and with realistic expectations to progress (i.e., not expecting to gain hundreds of points per week), it is an achievable goal.
I am rated over 2400 online (https://www.chess.com/member/ppandachess). I created a free course that will teach you a training plan to improve. Feel free to check it out: https://www.panda-chess.com/daily-improvement-plan
Do you think 1500 really hard to get in blitz?