I completely agree. Normalising AUTH-to-read for outbox relays creates incentives for relays operators to track each user's reading habits and and sell the data to advertisers.
The clients can already do that.
I can choose my clients but I can't choose other people's outbox relays.
That's true, but some clients ask you to approve AUTH to a new relay. If that's important to you, use those clients or ask your client dev for that feature. It could just be a toggle, or something "ask before AUTHing".
I just deny all AUTH in my signer. That waybindont have to find the setting in every client / believe they will honour it.