True it may be hard to find a dive buddy, but it is easier to find a dive buddy, than a bagpipe musician looking for a drummer to jam with!
But when I look at the data (PADI 2019 Worldwide Statistics - TREND BY AGE GROUP), for each of the last 5 years, there has been growth in certifications for both ages 10-19, and 20-29. Therefore, while some young people might face challenges to start or continue diving, according to PADI, certifications of young people is steadily growing that is contrary to your experience "I am concerned for the longevity of our sport because I see fewer young people becoming divers."
https://www.padi.com/sites/default/files/documents/2019-02/2019 PADI Worldwide Statistics.pdf
Perhaps some of the growth, are frustrated bagpipe musicians taking up scuba!
Best wishes in the new year!
Are you the piper or the drummer. If you're the drummer, i know where to find the piper and he's recently become a dive master, though I think his piping gigs are keeping him busy.