In my younger days, few people around would self-learn. Anybody who played an instrument including piano, guitar, flute and violin I assumed would learn from a teacher. A few decades ago without the Internet there were learning videos available but I hadn't seen anybody who learned on their own.
My first instrument in school was a recorder. After a year I learned a few Christmas tunes that I heard in church. I didn't push myself to learn anything more substantial. Then I learned violin in school out of convenience sharing the same instrument and teacher with my sister. We played the assigned pieces in a structured approach going through conservatory levels. My sistered took the first RCM level exam playing "Minuet in G" out of the "Notebook for Anna M Bach" relying on the teacher and making recordings on cassette to hear & assess her own playing. Today people would be able to find online videos of pieces a student would play from teachers & students.
A while ago came across online videos from a young man in Taiwan who's a self-learner. He posted a video playing a Chopin nocturne with a few missed accidentals (#/b) that the audience noticed. I've seen self-learners online who would play through Alfred's or Faber Adult beginner books starting at a basic level. And there are those who would jump into playing a few challenging pieces they always wanted.
The first year self-learning piano I didn't consider myself a total beginner. With experience reading music in the treble clef, took a while to get comfortable reading the bass clef but time went by quickly. I needed time to explore the piano and discover the repertoire I'm able to learn on my own. My parents aren't keen on the idea of someone self-learning without a teacher. I grew up in the East with a heavy focus on academics. The workload in school was very heavy. Unless somebody was taking music lessons with a teacher, he/she wouldn't be spending an hour learning songs on an instrument that would be better spent on homework & preparing for exams.