Having personally implemented a Unicode text renderer in both DirectX and OpenGL back in 2002 for the Japanese game market, I dare say that chances are that
I know a heck of a lot more than you about high performance multilingual text rendering. Don't presume.
You just made the exact same argument that Casey Muratori absolutely demolished very publicly.
The Windows Console dev team swore up and down that it was somehow "impossible" to render a fixed-width text console at more than 2 fps on a modern GPU when there are "many colors" used! This is so absurd on its face that it's difficult to even argue against, because you have to do the equivalent of establishing a common scientific language with someone that thinks the Earth is flat.
Back in the 1980s, fully four decades ago, I saw (and implemented!) colorful ANSI text art animations with a higher framerate on a 33 MHz 486 PC! That is such a miniscule amount of computer power that my iPhone charger cable has more than that built into the plug to help negotiate charging wattage. It's an order of magnitude less than the computer power a single CPU core can gain (or lose) simply from a 1 C degree change in the temperature of my room!
You can't believe how absurdly out-of-whack it is to state that a modern high-end PC would somehow "struggle" with text rendering of any sort!
Here is the developers at Microsoft stating that 2 fps is normal, and it's "too hard" to fix it. "I believe what you’re doing is describing something that might be considered an entire doctoral research project in performant terminal emulation as “extremely simple” somewhat combatively" from: https://github.com/microsoft/terminal/issues/10362#issuecomm...
Here is Casey banging out a more Unicode compliant terminal that looks more correct in two weekends that can sink text at over 1 GB/s and render at 9,000 fps: https://www.youtube.com/watch?v=99dKzubvpKE
PS: This has come up here on HN several times before, and there is always an endless parade of flabbergasted developers -- who have likely never in their lives seriously thought about the performance of their code -- confidently stating that Casey is some kind of game developer wizard who applied some "black art of low-level optimisation". He used a cache. That's it. A glyph cache. Just... don't render the vector art more than you have to. That's the dark art he applied. Now you know the secret too. Use it wisely.