What to get someone who has everything, for a milestone birthday
The people who have everything are the hardest to buy for, because the usual answer is another object they didn't ask for. Ask the people in their life to record a message for them.
Their sister might record one, or the friend from the first job, or the neighbour they've had for thirty years. Each person says what this person has been to them.
You can collect the messages in one of these ways:
Ask each person for a letter and collect them in a folder. Letters are slow to chase, and people put them off.
Make a group video, if the people you're asking are happy on camera.
Make a book of their voices. Everyone records from their phone, every message is written out in the book, and they can play each voice from its page.