> issues a write every time someone types into a text field
Assuming that an average person types at around 200 words per minute (number pulled from https://www.livechatinc.com/typing-speed-test/#/), that's a character every 300ms on average. With 10 people editing the document, that's a character every 30ms on average, which can easily lead to conflicts if they're all trying to update the same resource.
One of the strengths of event sourcing is that you can fix things after the fact. Say you got a wrong event like you suggested that conflicts. You don't check it at the time before allowing it in log. You notice the wrong event, delete it, and replay the log.
You can always replay the log to get you current point of time.
Updating a DB every 30ms should be trivial. Heck, you should be able to grab an exclusive row lock, double check your state, and write your change without even coming close - 100% conflict or deadlock free, regardless of the number of writers, simply by using a DB as it is designed to be used. In this case, by using the biggest reasonable hammer available: make everything sequential at the DB level. You can absolutely build other systems on a relational DB that don't have that limitation.