The disappearing RSVP

What happened to the RSVP?
You know, where you let a host know you'll be coming,
That little nicety of saying hey, thanks for the invite,
I'd love to come,
That little nicety of saying hey, thanks for inviting me,
So sorry to miss it
Let's catch up soon
Happy holidays.
What happened to hand written invitations that
Reliably arrive in a mailbox
Eagerly opened, treasured
Now an eVite, never received, or worse,
Viewed, but never replied,
Maybe something better will come up.
What happened to the RSVP, gone the way of
Other good manners I grew up with
I must be old.