I took the phones of my parents and siblings to install Telegram on them myself ;) My brother and sister use it sporadically, but I still can send them messages knowing they will read them sooner or later. My parents are more proficient with it than me, now :).
This was always the problem. Your social media environment and opsec too relies largely on your social graph that you have no control over. Maybe LLM based scraping/automation solve this mid-long term?