Telegram has a feature where it will delete your whole account after 3 or 6 months of inactivity. That's how my friends can now. :)
It is not complete if you want to send them anything after you go—some goodbye letter, or something more practical like a password, or plans and info they should know.
It is still a good idea to configure anyway. It's not one tool or another; they can complement each other.
The people who i am thinking of can have access now. They just wouldn't know what to do with it.
You could then share the complete instructions via email using a dead man's switch, which would make it easier for them to navigate those difficult times.
If you want to give that a try, I can answer any questions you have during setup and extend the free trial (the default is 14 days) until you are sure that this is the right solution.
Send us a message if we can help!