The thing about a car is when the bumper gets detached you can't just strap it down to the front of the car and wait until it reattaches itself.
It may be (surely is) that something like lupus is multifactorial and impossibly complex, but knocking out the largest cause of something can be a reliably cure.
Look at antibitoics - a truly "replace the sparkplug" fix for let's say treating a MRSA infection. Doesn't treat cell damage, doesn't treat inflammation, doesn't treat pain, doesn't treat hormonal imbalance through the body. It doesn't even target the specific infection it kills indiscriminately. Yet "give them antibiotics until the MRSA goes away, or if it doesn't give them more antibiotics until it does" it super hand-wavy.
It may be (surely is) that something like lupus is multifactorial and impossibly complex, but knocking out the largest cause of something can be a reliably cure.
Look at antibitoics - a truly "replace the sparkplug" fix for let's say treating a MRSA infection. Doesn't treat cell damage, doesn't treat inflammation, doesn't treat pain, doesn't treat hormonal imbalance through the body. It doesn't even target the specific infection it kills indiscriminately. Yet "give them antibiotics until the MRSA goes away, or if it doesn't give them more antibiotics until it does" it super hand-wavy.