Mail has always felt like garbage to me. Notes, I will have to give a try again. Though, really, the entire "office suites" that everyone makes always feels off to me. I will full cede that that is just preference.
Safari feels off, as well. But I'm pretty firmly in camp firefox.
When I think bundled apps, I think of their notepad equivalent. The finder. The calculator. And... that is about it. I remember trying to make a script once, and that script editor left me very very lost.
This is a bit interesting to me, which bundled apps don't feel modern to you? Mail, Notes, Pages, Safari... they all seem modern enough to me.