This should reduce friction with that though because unlike someone walking up to you with a card, it's an app you can choose your level of participation in!

We hope that this will be more natural since people typically send birthday wishes in Slack anyway

Writing "Happy Birthday, <name>!" takes literally a few seconds and absolutely 0 effort, but means a lot to the recipient. You should consider your coworker's more empathetically

The times they are a-changin' - this week I signed a card remotely, a PDF one through Adobe Acrobat Reader.