I think you’re missing the point. Most places, with a few exceptions, have hotels which are luxury and not luxury. We pick luxury hotels for a variety of reasons but most of us wouldn’t stay in an environment that was worse than our own homes. The same applies to toiletries - I don’t like to use something nasty that is mass produced and full of chemicals. You’re not quite right about brands standardising toiletries; if anything I’ve found that luxury brands whether they are part of a chain or not have autonomy when choosing what they offer.

Four Seasons - property specific
Dorchester Collection - property specific
Oetker - property specific
One&Only - property specific
Aman - property specific
Jumeirah - property specific
Mandarin Oriental - property specific
Park Hyatt - property specific

So you see a lot of luxury brands allow the hotel to stock bathroom amenities which fit the property and environment. Other than St Regis and Peninsula I can’t think of another luxury hotel that standardises bathroom amenities across all properties. You may disagree but I think that’s part of separating luxury from non luxury. I think standardising shows a lack of discernment and attention to detail. Certainly on this forum there are lots of contributors who feel quite strongly about what bathroom amenities they use as well as the hard & soft product. There was a thread on this a few years back and I was surprised how many like minded contributors there were.