Why cant we have a sent time and the receipt time ? The time the sender claims the client sent the message be appended to the message itself. Let it reach 500

Why cant we have a sent time and the receipt time ? The time the sender claims the client sent the message be appended to the message itself. Let it reach 500ms or 2 seconds later. If there is an acceptable skew between the sending time and receiving time, we just accept the sending time. Edit: what this could do is, the sender when they sent the message, they were aware about x messages before and the clocks being in sync for existing messages, their message even if received 2 seconds later would be put in the origiNAL order of sender intention