Evento JavaScript de vainilla cuando alcanza el fondo del elemento no jQuery

window.addEventListener("scroll", () => {
    var offset = element.getBoundingClientRect().top - element.offsetParent.getBoundingClientRect().top;
    const top = window.pageYOffset + window.innerHeight - offset;

    if (top === element.scrollHeight) {
        console.log("bottom");
    }
}, { passive: false });
Diz Andriana