And social media websites that allow porn (Twitter, Reddit, Lemmy, Tumblr)

Or just messaging apps where people send each other porn anyways (Whatsapp, Discord, Telegram)

Horny teens have always found ways to get their hands on porn, even before the internet. Studies from the 80s and 90s found that the same percentage of boys had accessed porn as more recent studies where the internet has already become widespread:

A study by Bryant [13] indicated that by the age of 15 years, 92% of boys had looked at or read Playboy, with average age of first exposure reported to be 11 years. Similarly, in regard to X-rated films, 92% of 13- to 15-years-olds reported that they had seen such a film. Most undergraduate men, when asked whether they have used sexual media in the past year, answer in the affirmative, although results vary between studies [14,15]. Studies in other cultures have found similar exposure patterns as in America. A recent study of 517 young men aged 18 to 27 years in Hong Kong indicated that 15.8 years was the average age of the first purchase of sexual media; just over half reported having used sexual media in the past 6 months [16]. The overall prevalence of having read, watched, or listened to sexual media in this sample was 91% (see Pan [17] for a lower prevalence estimate among Chinese young adults).