How much would you be willing to pay for such a client?
I'm not being facetious, I'd really rather like to know, because as an independent developer, every single time I suggest a native application using native widgets to a client, they choose the HTML interface rather than a Qt or similar based interface.
The easily doable pretty animations in CSS in a 800MB-in-RAM-while-running application is, to paying clients, preferable than a 50MB-in-RAM-while-running that doesn't have the fancy spinning, tilting, animated wizz-bangs.
I have been writing software professionally since the mid-90s; I can do you a quick GUI-based cross-platform HTTP send+receive application based on libcurl in about 2 weeks. Looking at the minimum I need to make to pay my bills, I need purchasers paying a cumulative 1000USD for this effort, so 10x buyers @ $100, or 100 buyers @ $10, and so forth.
And, of course, I'd expect to only be able to sell it for a short while, if it is popular, until a clone starts up with $40k worth of SEO and advertising money.
The software you want can be had, and the skill to make it exists, in a timeframe that is feasible, but the economics are just not there.