One person organizes it, coworkers chip in by card from a link, and the total is visible to the group. Someone retiring after decades deserves a gift handled cleanly, not a cash envelope and one volunteer's memory.
Someone retiring has usually touched a lot of people across a long career, which is exactly why the collection sprawls: current team, old team, people in other offices, the ones who left years ago and still want in. Run that on an envelope and one organizer ends up with a pile of cash, a half-remembered list, and the job of fronting the difference at checkout.
Retirement gifts are the ones where people say "I would have chipped in if someone had asked me." A link fixes that: it can be forwarded to a former colleague, dropped in a company channel, or sent to another office, and each person chips in what works for them. The intern and the director don't give the same amount, and nobody has to say so out loud.
When the collection closes, the record shows exactly who was part of it, which is what you want for the card and the speech. The money goes directly to the organizer through Stripe, TableCash never holds it, and the app is the record everyone who gave can open. A departure that isn't a retirement works the same way, see collecting for a coworker's gift.