Gabetos is a regional, somewhat old-fashioned Spanish word for 'drawers' or small storage compartments, the kind found in an old piece of furniture. It's not a word you'd hear in everyday pop music, which makes it feel personal and almost nostalgic.
In the line "Los gabetos por lo que fueron" (The gabetos for what they were), the word suggests old drawers holding onto memories or things from the past, kept but no longer quite the same as they used to be. It gives the song a quiet, bittersweet sense of looking back.
Esteman opens "Los Que Fueron" mid-thought: "Decía yo, un rezo más" [I was saying, one more prayer], like we've walked in on a ritual that was already running. He keeps circling one question instead of answering it: where do the people, and the beliefs, we lose actually go? "Cuestionar lo que no ves" [To question what you don't see], he sings, is almost its own punishment.
The chorus never gives him an answer, only the same absence again and again: "Se van y llegan más al olvido" [they go and fall more into oblivion], "Adonde fue y donde esta lo que vivimos" [where it went and where is what we lived]. He never names "los que alteran bases del ritual" [those who alter the foundations of the ritual]; whatever they built dissolves before he can point to it, and the song closes exactly where it started, on "Los que fueron se van" [those who were are leaving].