Let it be said first without irony: the spas in this city's better hotels are genuinely good. The therapists are trained, the towels are warm, the pool is lit like a jewellery case. The argument here is not against their quality. It is against the walk, the schedule and the shared nature of the thing, three costs the brochure never itemises.
The schedule is theirs
A spa is a diary you must fit into. Treatments run in slots, the last slot leaves with the daylight, and the precise hours a travelling body most wants working on, after the late dinner, past midnight, the jet-lagged four a.m., are exactly the hours the facility is a locked glass door. This house keeps the opposite calendar. The session starts when your evening actually ends, whatever the clock claims, and no printed timetable is consulted on the way.
The venue is shared
However serene the treatment room, you reach it through a public building and give it back afterwards. There is a robe, a corridor, a locker with your watch in it, another guest's slot pressing on the end of yours. Upstairs, every one of those disappears. The room is already yours; nobody has it booked at nine; your own shower is four steps away and your own bed is two. The session does not end with dressing and walking anywhere, it ends with you already exactly where the rest of the night happens.
The attention is divided
A facility serves a building's worth of guests with a handful of staff, and its therapists work a shift of strangers in sequence. The woman who comes up is working for one person tonight, or two, if two were booked. The form and the length were settled in the message thread before she left home, and she names her own limits before she starts, while the pressure, the silence or the conversation are settled with you in the room. That narrowness of purpose is not a luxury add-on. It is simply what bodywork looks like when the venue stops imposing its own logistics on it.
Samanta, who worked hotel spas before she worked this rota, puts the whole argument in one line: downstairs she treated the appointment, upstairs she treats the guest. The building's real treatment room was never behind the glass door by the pool. It has your do-not-disturb sign on it already.