Booking links solved half the problem — and created a new one. They removed the back-and-forth by handing your calendar, and the work, to the other person.
A booking page is your open calendar, browsable by anyone with the URL. People can see exactly how free (or swamped) you are this week, infer when you work, and watch your availability change day to day. Forward the link once and that's true for anyone downstream, forever.
Darwin offers two or three specific times he chose for you. Nobody ever sees the calendar behind them — not the gaps, not the events, not the pattern. The difference between "here are three times that work" and "here is everything about my week, pick" is the difference between an assistant and a self-checkout.
Sending someone your link asks them to open a page, study a grid, and fit themselves around you. Plenty of people read that as "my time matters more than yours" — which is why so many senior people simply won't use one. An email from an assistant offering concrete times is the etiquette that has worked for a century. Nobody has ever been offended by it.
Booking tools express what fits in a form: buffers, working hours, minimum notice. They cannot express "Fridays only if it's an investor," "coffees near the office, video for everyone else," or "this person has rescheduled twice — check with me first." Darwin takes preferences the way a human assistant does: written in plain words, applied with discretion, different for different people.
Group scheduling across companies, a reschedule negotiated mid-thread, an external organizer who needs chasing, a day-before confirmation — that's the actual work of scheduling, and it's all after (or instead of) the link. Darwin does the whole conversation, not just the calendar write.