You decide how happy you are with the work you do. You just have to decide that's what you want to do and you will make the decisions necessary to make the rest of it fall in place. I've decided that I want things in life that aren't compatible with the Big 4 lifestyle, from what I've heard of it, so I've decided not to go that route…but I've decided to be happy with the route I've gone. I really really think that attitude is the biggest part of contentness with any job. You can be happy cleaning stables, working fast-food, auditing F500 companies, or counting beans, all depending on your attitude and the choices you make.
So, my advice would be to realize that you control your happiness (not necessarily what happens to you, but definitely your responses, and therefore your happiness), so if you want a long-term career in public accounting, then realize that you're choice and decide to be happy with it. Don't listen to the people grumping around you. Know what you want and why you're there, and ignore all the grumps that say otherwise. Every job I've had I've loved, and every job I've had, I've worked around people who thought the job was terrible. Have you seen the ad on TV for a job search site (I think it's Indeed, but not 100% sure) that shows a guy whose job is to give massages to sexy models all day, and he's complaining about it? People can complain about any job.
Don't let the fact that someone else doesn't like your job make you not like your job. Love your job if you want to love it. Then make life choices that will allow you to continue loving it. (For example, having 8 kids that are all heavily involved in sports with spring seasons might not be the right choice if you're in tax and audit, since you'd never get to go to their games. So, you might make a life choice to not have kids or not have as many or to homeschool them and have them travel with you or etc. etc. etc., point is to make life choices that all fit together. If one life choice is to work in public accounting, then make other compatible life choices. You can't make a life choice to live at the equator and in the Antarctic at the same time.)