Forget where that's from, but seems true of companies too. Each company I've joined had skeletons you'd never see during an interview. After the honeymoon period wears off, the truth starts to show.

Not to say that you shouldn't find a new job. Definitely don't expect it just get better though.

In fact trading the known badness of your current company for something else gives you opportunity to find different ways a company can be dysfunctional. Enough of those experiences and you'll get good at pointing out dragons before they get nasty. Truly valuable for a senior developer.

I think that in software there's something similar. Maybe you'd have more fun in a software company, where what you do is central to the business. Anyway, don't give up hope! There are jobs out there where you'd be having a lot more fun every day.