Good question, because I think speed is more about mental load than literal time. From my experience, the biggest thing is clarity upfront. If I land on a booking page and immediately understand what’s included, what it costs, and roughly how long it’ll take, I move forward without hesitation. One service I used recently did this well — everything was laid out step by step, no account creation, no surprise add-ons at the end.
Another key feature is smart defaults. Instead of asking me to configure every detail, it suggested common options, which I could adjust if I wanted. That alone saved a lot of time. Also, real-time availability matters — I hate picking a time only to be told later it’s not available.
I noticed a similar approach on detaily , where the flow feels more like a conversation than a form. You’re guided, not interrogated. That’s what makes sub-5-minute booking realistic for me. If I have to stop and reread things, the system already failed.

I agree with both of you. For me, trust signals are underrated in fast booking. Even if the process is quick, I slow down if something feels off or vague. Simple language, visible pricing, and not forcing sign-ups make a big difference. When those are in place, I’m comfortable finishing fast without second guessing.