GTM ClubAn AE is measured on closed revenue, which makes them the customer of everything upstream: if the SDR's meetings are bad, the AE feels it first. The best AEs also prospect their own accounts, especially the large ones where the buying committee needs a senior voice from the first touch.
In founder-led companies the founder is the AE, which is the point: nobody closes the first fifty deals better than the person who built the thing.