To read 1 Peter 2.24 as a physical healing, you really need to cut the last part of the sentence out of its context.
But the full text is this:
"He himself bore our sins in his body on the tree, that we might die to sin and live to righteousness. By his wounds you have been healed. For “you were like sheep going astray,” but now you have returned to the Shepherd and Overseer of your souls."
The healing is spiritual, about sin, about not being gone astray, about returning to the Shepherd of our souls.
The full text says "you have been healed for you have returned to the shepherd of your souls".
This is the healing.
But the full text is this:
"He himself bore our sins in his body on the tree, that we might die to sin and live to righteousness. By his wounds you have been healed. For “you were like sheep going astray,” but now you have returned to the Shepherd and Overseer of your souls."
The healing is spiritual, about sin, about not being gone astray, about returning to the Shepherd of our souls.
The full text says "you have been healed for you have returned to the shepherd of your souls".
This is the healing.
Here is the full text in Isaiah 53:3-6
3 He is despised and rejected of men; a man of sorrows, and acquainted with grief: and we hid as it were our faces from him; he was despised, and we esteemed him not.
4 Surely he hath borne our griefs, and carried our sorrows: yet we did esteem him stricken, smitten of God, and afflicted.
5 But he was wounded for our transgressions, he was bruised for our iniquities: the chastisement of our peace was upon him; and with his stripes we are healed.
6 All we like sheep have gone astray; we have turned every one to his own way; and the Lord hath laid on him the iniquity of us all.
This text differentiates clearly about two things here: Our transgression and healing.
It clearly says his wounds and bruises were for our transgression and iniquities. While his stripes is for our health and healing.
It is from this same scripture that Matthew quoted from in Matthew 8:17 which you affirm, is talking about physical healing, which is a part of what Isaiah said.
Then Peter in 1 Peter 2: 24 goes a little further than Matthew in his quotation of Isaiah. He added the atonement for sin part of the book of Isaiah and the going astray aspect.
These scriptures clearly in a no-brainier way, tells us that Jesus paid for our sins by his wounds; and then he paid also for our physical health and healing with his stripes. Then the going astray part, emphasises the atonement for sin part of his atonement. And of course, that does not in anyway nullify the physical health part.
This is dead brain easy to understand. Even a total dunce can understand it. Why try to complicate the interpretation to support your belief?
If you agree that Matthew 8:17 is talking about physical health and healing. Why do you have problem agreeing that Peter is also talking about physical healing; when both Matthew and Peter are quoting from the same text?