No, google docs is not just text entry, it is much more complicated than that due to synchronization and they did not try to optimize it well IMO. Text entry, even with highlighting and rich text, can be fast with web app, see VSCode and markdown applications for example.

As an example, see Atom vs VSCode. We thought building a code editor with electron will lead to something slow like Atom, but m$ later proved that it is possible to build something fast. Perhaps not as simple as native, but it can be done.