Exactly so. If I'm going to do anything with it later, I'll have to read it again anyway.
It's self-culling with time. I've got unread messages deep down on the list. Things that I wanted to do something about months ago, but never did, and they weren't important enough to come up again. And if they ever do come up again, I can see that I received a message and didn't do anything with it.
And then while checking your email you mindlessly click it and realize its the one you have "snoozed" by marking it unread, so you need to mark it unread again.
Now I have a keystroke that will automatically create a TODO with a link to the message. I hit the keystroke and then archive so it no longer shows up in my inbox.
There are lots of poor productivity books/hacks, but the "Do not treat your inbox as a TODO list" has stood the test of time.
What if you read an email, and need to do something, but can't do it right now? Do you mark it as unread so you can deal with it later?
I did that for years. Thankfully no longer!