Honestly it sounds a bit desperate. I'm not dissing the idea of getting a PhD, I think it's a big achievement. But this sort of argument is the kind of thing I heard when I finishing my undergrad, and it wasn't convincing then either.

Grant Applications:

Very specific academic "skill" which is intimately tied to the bureaucracy of the university system of your particular country or region. It also has a lot to do with things that aren't even in the application: who you know and what they think of you. Whatever org you join later will have some other way for funding to come down, and there are so many varieties of org that you'll just have to learn on that job.

Analyzing Data:

That's definitely useful, but there's general and specific. There are lots of people who can't do it, and by doing a PhD you definitely show people that you are capable. But, and it's a huge but, you will be spending a heck of a lot of time poring over the evidence on some very specific area of science, with its own conventions and paradigms. When you go and do something else, that won't be relevant. People will of course see that you are generally intelligent, and that's great, but you'll have to learn whole new fields at your next gig. Your issue then is that it's possible to show general intelligence and ability to learn deep material without doing the whole PhD. In fact plenty of people will look at a Bachelor's and conclude the person is smart enough to learn how derivatives work, or how the advertising business works, and so on.

Presentations:

There's simply no less efficient way to learn presentation skills than to do a hard science PhD. It doesn't make any sense, a PhD takes a lot of work and how much of it is actually doing presentation specifically? Yes, I know they do presentations as part of it. But the kind of presentation skill you want is what your typical smooth talker is good at: confidently being able to talk about something that everyone can relate to. Think Obama or one of those Apple-guy-on-stage things. Are you going to learn that on your PhD? From what I hear, science fields are very very specific and although you are presenting, there's a fair bit of focus on the substance, plus you are presenting to people who are also insiders. If you want to just be less nervous and uhm-and-aw less, there are better ways to practice.

There are of course good reasons to get a PhD, such as a desire to learn that specific field. But the cost/benefit of doing it in order to learn generally applicable skills seems off to me.