That one's easy: No. Don't worry about 8K for now, despite what you might have heard about it and that the HDMI 2.1 standard supports it. 8K is 7,680 by 4,320 pixels, or four times the number of pixels of 4K. 8K TVs are currently available as premium models for significantly more money than their 4K equivalents (including OLED TVs, which are already pricy), but they aren't going to be meaningful for consumers for a few more years, and there's little reason to consider buying one yet unless you have lots of cash to burn. Moreover, there's no consumer-ready 8K media available, and no major studios or distributors have even talked about releasing 8K movies or shows so far. There aren't yet physical or streaming media standards that could support 8K commercial releases either. Even if you can find an 8K TV, at best you might be able to watch upconverted 4K video on it. So, for the time being, don't worry about 8K suddenly replacing 4K. It won't happen anytime soon.