Do you think they're the greatest invention since the zipper, or do you think they are just glorified leggings masquerading as pants, and should not be worn without a tunic or dress?

I just got my first true pair, and they are soooo comfy. And the SA promised me they will not bag out at the knee like skinny jeans can, which makes me happy. But sakes alive, they are TIGHT. I've tried them on with long-ish tops and I think they look good, but a bit of my derriere is visible and I'm wondering....how tight is too tight? Is it OK for a nearly-forty-year-old woman to wear skintight pants? (Or any woman?). I've got the legs for it, and the tops I would wear are not revealing. And there are no VPL or muffin top issues. But if these had existed when I was a teenager, I would not have been allowed to wear them!

ETA: my jeggings have a zip and real back pockets, like proper jeans. The texture is like jeans, and they are relatively thick -- thicker than leggings. But they are much stretchier than jeans, and as a result cling mercilessly to every dip and curve.