You're not really mistaken. You can do some interesting things with eggs--very precisely control the texture of both the white and the yolk (which relates to the coagulation of different proteins). But, for the most part, I use sous vide for meat and, especially, red meat. I'm not sure I'd say you need to eat a "lot" of meat (it's not like I use my sous vide setup every few days) but it is primarily for meat.
I must say that I've never tried it with chicken thighs. I do use it with boneless breasts now and then for when I want some cooked chicken for a salad or noodle dish. It really helps keep the meat nice and moist while being cooked just right.
Like traditional BBQ (e.g., low-and-slow cooking over coals) sous vide is most interesting when applied to meat, especially cheaper cuts that would normally have to get boiled, braised, or roasted to within an inch of inedibility before being soft enough to eat.
That being said, my absolute favorite thing to prepare sous vide is carrots. Lots of other root vegetables (turnips, burdock, sunchokes, new potatoes) can similarly be cooked in a water bath to a temperature just high enough to soften them without extracting flavor or nutrients via boiling, steaming, or sautéing. I've also had good luck with green beans, asparagus, and broccoli rabe.
Finally, if you're pescetarian seafood is also a great option. I'm not sure I'll ever cook lobster any other way after seeing what whole (shell-on) lobster tails are like cooked sous vide with a healthy dollop of butter.
The low-pressure vacuum sealer doesn't do anything for vegetables, but chamber vacuums burst the internal air cells in plants and can significantly change textures to an amazing degree. (This is separate from the actual cooking process, which itself can change things, but not to the degree that occurs for meats.)
