HEK was used to test common OTC drugs for ridiculous reasons, but it has not been used in the creation of all drugs.
For example, older medications like aspirin and metoprolol do not owe their existence to HEK293. Big difference.
No drugs “owe their existence” to HEK. It’s a test bed for checking safety including for the OTC painkillers that you’re trying to exempt from your guilt by association game.