Visa to China sounds like a winner: Never had to do that myself, but it seems arcane, shady magic that some friends from Hong Kong know how to perform whenever we needed to go.

There are plenty of these infrequent, but non-zero, official, lifestyle and corporate customer processes that are PITAs, for a variety of reasons. People would gladly pay to avoid the hassle themselves, where cost-efficient, eventually-expert, standardized "schlepping" can make a good business model or 10. Relieve pain for $; enough people will gladly hand you $ to make it happen.