I'd get rid of it.

No need to keep that wall, especially if you want a smaller vanity and the space to be more open. It will be a nice bathroom if you simplify and make it feel more spacious, and renovate according to your taste. Go for it!

Get rid of it. I might feel differently if there was just a small private "toilet room," which is nice to have if the bathroom is shared, but in your case the bathtub is also in there. What's the point?

I'm redoing my master bath and the contractor just took down half the wall (leaving a pony wall) between my shower and toilet - the room feels HUGE now, light and airy.

I wish I'd done it decades ago. Of course, I didn't have the money to do it decades ago :-).

You could turn it into a pony wall and shorten the length so you have a place to attach a TP holder. Otherwise you'll need to attach it to the vanity, which brings the TP in closer to you and is a little more awkward to use. A pony wall also keeps your toilet centered in the space between the wall and the tub rather than adding 6" more floor space between vanity and toilet. But if you're doing a custom vanity, you can add that 6" to the vanity.

I'd take 'er down.

I got rid of mine, and also went from two sinks to one. The room is more spacious, and plenty of room for a free-standing TP holder.

I'd cut it down to a half wall and then put a piece of opaque glass on top of it for privacy.

That would look sharp. Otherwise it's like a million other bathrooms--including mine!

Prefer to remove but a great alternate is do a pony wall.

I would remove the wall and use a single vanity.

Get rid of the wall. I think the current trend towards divided bathrooms is a mistake; it makes already-small rooms feel claustrophobic.