But in practice, you have to have the appropriate product implemented and supported well, it has to be marketed well, and you need the staff trained and willing to serve the customer, and you need all these facets to meld together to provide the optimum customer experience.
Your challenge with this, imho, is that you do not seem to accept the fact that in large/very large organisations, there are people who are not as customer-focused* as they should be, and they can be difficult to re-educate/remove, and thus some customers receive sub-standard service (which is wrong, but so is getting wet whilst waiting for a bus, but sometimes, stuff happens). You may have experience running a small "virtual" business, where you can be very "hands on (even in a virtual sense)" with the small number of employees you may have, but the challenges involved when you have multi-site, multi-disciplinary teams of tens, if not hundreds, of thousands of employees, with a vast range of independent and/or interdependent products and services, is a completely different matter - you can spot/fix a "bad egg" if you have a couple of employees fairly quickly, but this is much more problematic when you increase that number by the tens of thousands.
Now, this is not excusing sub-optimal customer service, but trying to explain some of the reasons why it occurs.
So, as I said originally, If only life were that simple........
*to put it nicely...