Why ruins of Ostia and Pompeii are counted as “ancient Roman” meanwhile in reality they’re made not earlier than 15th century AD

The burned bricks of ruins of Ostia and Pompeii are made using technology of Aristotele Fioravanti, also there are mosaic with pineapple in Pompeii (the fact that pineapple was brought into Europe from Brazil not earlier than 15 century AD), also there was Venetian glass in Pompeii that is also technology of renaissance era, also there was Jesuit - Mascolo, Giovanni Battista, (1582/3 - 1656) he made a drawing of Vesuvius eruption in 1633, but slice of soil made in 1976 in expedition to Pompeii proved that eruption was only once. So there’s a question why historians are going against logics and lie so much to us?