It's illustrative to remember who and what started this: nVidia's practice of intentionally undercutting their manufacturing partners. See, manufacturing partners tend to apply secondary binning of their cards and sell them with an overclock thus delaying their obsolescence for a year or so, and that's bad when you're in the business of selling the chips themselves (while neutral to the secondary manufacturers; you just buy a new GPU from them a year later, who cares).
So it really isn't a surprise that that, combined with artificially limiting supply for the 40-series GPUs (and most of that allocation is likely going to be to, well, themselves), and now the fact that the price that nVidia likely demanded for those GPUs is coming around to bite the secondary manufacturers, meaning that they all bought (or were required to buy) the GPUs at inflated prices, they're leaving the business.
And guess what manufacturer wasn't forced to pay that premium? That's right, nVidia! So they alone have room to drop prices and still make a profit, while making the value proposition even worse for the secondaries (price premiums for overclocking make less sense as they diverge from the base model and those improved coolers are more expensive to make than nVidia's solutions).
EVGA is understandably the first to bow out; they've never dealt with AMD (who have supply problems for other reasons), whose GPUs haven't been the premium product for a while (arguably, ever), and if they say it's no longer profitable even before a primary usecase for GPU compute vanished overnight I'm inclined to believe them.
And sure, there are still going to be secondary manufacturers producing cards, but most of the other manufacturers are either do-all companies (large OEMs more famous for motherboards and laptops), produce AMD cards too (Zotac-Sapphire-Inno3D), or are otherwise diverse enough (PNY) that ramping down production wouldn't kill them as a company...