Should there be read receipts in chat applications? What are the pros and cons?

I am building a chat application.

One of the things I'm wondering is whether read receipts, like many chat applications have, are a good idea.

There are essentially four options:

• No read receipts
• Optional read receipts, default off
• Optional read receipts, default on
• Mandatory read receipts

On the one hand, they certainly provide useful information to the sender. On the other hand, they can also provide misleading information. For example, when a user is driving and they cannot respond, the sender may feel ignored. See Read receipts make people feel terrible and you should turn them off

It tend to agree with much in the article, but at the same time, most chat applications like WhatsApp, iMessage have at the very least optional read receipts, so this functionality may be expected. On the other hand, Slack has never had read receipts and many users don't seem to want this. Is it context-dependent (work vs. friends)?

Optional read receipts seem to provide a sensible middle ground, but even this has a significant impact on the dynamics of the conversation, and turning them off may raise questions as to why you turn them off, so this only provides a partial solution at best.

Because of all of this, I'm leaning somewhat on the don't have read receipts side, but I'm really not sure.

Any thoughts or studies on this?