Why would it be more difficult to escape your caste in rural India today?

I believe the phrase "escape your caste" in the question
is used to refer to not being subjected to, or influenced by the cultures and customs
specifically associated with the caste of a person. Meant this way, the statement about
nature of cast system in rural India (as compared to urban India) is definitely
true.

We can examine this question more meaningfully by
first understanding a few things about the caste system itself. The caste system in
India is not about just dividing people in small groups. As a matter of fact it was more
about uniting people, and promoting individual behavior that promotes common good of
all. Centuries back, when the concepts of democracy and individual freedom was unknown,
it provided means to small groups of people to govern themselves democratically, for
promoting common good of the people. This also included protecting the group from
outside negative influences.

These cast-based
self-governing, democratic systems had to be small in those days of limited
communication and transportation facilities. Thus each self-governing group consisted of
people with similar profession and culture, residing in a small geographical area. The
value of such system was recognized by the great social reformer and champion of
equality, Mahatma Gandhi. It is important to note that Mahatma Gandhi, who made great
contributions to highlight the evils of caste system in India and to rid the Indian
society from those evil, also worked to promote the panchayat
system which is the old Indian system of democratic self-government in
villages.

Unfortunately, in spite of the original values
and good intentions of the caste system as explained above, this system also created
rigidity of behavior within the castes, and divisions between different casts. This
might have been desirable to some extent in the past, but in modern democratic system,
and the technological and economic need for integration of people it is no longer so.
People in India have been slowly recognizing the negative impact of caste system in
current situation because of actions of reformers like Mahatma Gandhi, and also because
of the difficulties and limitations faced by individuals in practical
life.

In response, the rigidity of the cast system is
breaking down with a pace that is proportional to the problems of the caste system faced
by people. These problems are faced more in urban areas where people find it more
convenient and beneficial to base their association with other people on grounds other
than caste. Thus people give much more weightage to factors like education, profession,
financial status, political affiliations, business associations, and common interests
(say like music). This kind of need for change is felt less in rural areas than in
bigger cities, with greater degree of industrialization, commercialization, education,
and presence of people of many different caste within a place or institution. This is
responsible for the difference in the influence of caste system in rural and urban
areas.