I listened to a podcast interview with one of the cofounders of zed. One of the revealing things is that he went on and on about how important latency was and how they had to do their own rendering because of the problems they ran into with electron. He also admits that he never used vim, which already has imperceptible latency relative to the terminal emulator, which has already largely solved the text rendering problem.
I understand that there are advantages to being a native app from their perspective, but for me, it is even better for my editor to be integrated into my terminal editor. And because they built it the opposite way though, they have to also build a terminal emulator into their editor.
There is a real cost to building zed this way. If they were an embedded terminal app, they would get full terminal support for free and would not have to implement 2d text rendering. They could even have made a bundled package with an oss terminal emulator like kitty. Then they could have focused strictly on their editing features and value adds. Every engineer hour spent fixing bugs/adding features to the rendering framework is an hour that could have been spent on value adds.
Personally, there is no way that latency itself can be that value add for me because I use neovim and don't use any language plugins so every keystroke already renders instantly. Clearly then you can do everything zed does in a terminal app within at worst tens of milliseconds of latency.
Of course their target market uses vscode and not vim and either doesn't know or care that you do not need to write your own rendering engine to make a low latency, featureful text editor. I am admittedly very much not the target consumer for zed though.