Because what you've described isn't a laptop but a shitty desktop computer. Laptops that large are heavy, which sucks to travel with. Such a monstrosity isn't convenient to throw into your bag and bring with you everywhere all day. If you're not even using it for graphics, get a desktop, install Tailscale, and remote in for your shitposts.

Is the opinion, anyway. Nothing wrong with your opinion (or mine), they're just opinions after all, but if I was on my feet all day in the field and needed a laptop, I'd rather something small and light with a long battery life. If I wanted something luggable, I'd go for a usb-c monitor and as small a desktop chassis as would fit a proper GPU inside of a mobile one. But dealing with the cables for that would get old real quick, so a laptop like you describe would be my pick in those circumstances. Eg my friend's a VJ and performs at random clubs and a gaming laptop like you described is the most appropriate device.

Because the magnitude of demand similar to yours is so low, that I doubt many manufacturers can exist profitably in that space, hence Toshiba and others exiting the market.

You want a gaming laptop.

I agree. I am typing on a Macbook Air but I don't like it much. Too thin, terrible keyboard, terrible buttonless trackpad. It has almost no ports and no expansion. There's no easy way to middle-click without addons.

The only reason I use it is its battery life. Work provided it; it's not mine and I'd not choose one myself.

For my own, I want a big thick chunky thing with 3 physical mouse buttons, lots of ports, a swappable (and ideally hot swappable) battery and ideally 2 of them.

There's a space for thin'n'light, but there are next to no commercial options for those who want fat'n'flexible.

I absolutely agree. There are such clear benefits to thicker and heavier laptops. Drawbacks as well, obviously, but it is crazy how lopsided the market seems to be in favor of compactness, even at the cost of power, battery, and reliability.

Same applies to phones.