i have no idea who that is. and lighting doesn't have anything to do with witnesses discount

Bitcoin conserves demand for blockspace. Demand for blockspace can only be paid in sats by individuals up front or paid in bits as a tax on all nodes that must be paid in perpetuity as a forever maintenance cost in time. Pick one. Low time preference is to pay in sats rather than bits. No free lunch...

Lightning doesn't require the witness discount, it only requires segwit as in "segregated witness" so that there is txid malleability risk

Can you explain how would it kill lightning?