I am nearing that age, but the displeasure started several years ago. I find myself a bit trapped with a a place where I am marrying 2 specialties that tend to go together, and that in theory should be an ideal job. But hte people, politics, and lack of genearl teamwork have left a sour taste. And it's not like I am ready to give up the money I save (I make a bit more because of the industry but still a lot less then others in this field). And since I am on an immigration visa, it's not as easy for me to hop around from place to place. A bit lost at what to do. Its not as if I am not following my heart because I think I am, I just do not like the environment, nor will it be any better at another unknown place.
I'm the same - only just pre-30 but already tired by being the "expert" at what I do (I've tried repeatedly saying that "knowing a bit more about something than other staff here" is a shitty bar for "expert" status and they should get rid of me and replace me with someone who's genuinely good at it, and interested in it, alas, nothing).
Other people might kill for my job, but honestly, it doesn't excite or engage me, and each day is literally just a march to get home and play with building my own stuff.
I've worked in cyclical industries (education and yearly hiring cycles) pretty much since leaving university - I'd advise people to avoid these if you can unless you love redoing the same work time and time again (but with enough enforced differences so you actually do have to do it all again). The "Start > Push > Reset" cycle is inherently demotivating to me.
Ideally, find something that compounds - where your work contributes to some kind of growth - rather than resets to zero again.
