My Thunderbolt stopped working out of the blue. I believe it is a hardware issue
as I've tried various thunderbolt devices and cables and none work. Furthermore.

Within the system info – I get “Thunderbolt: No hardware was found.”

I tired resetting the pram and smc but none help.

Could a fresh install of the OS help?

Could a fresh install of the OS help?

Doubtful, but you can at least rule that out if you do it. Sounds like you need to book an appointment at he Genius Bar.