While sharanagati shall fructify and it can be done for any want; what if a sharanagati done by an Akincanyan for worldly benefits with absolute faith does not bear results? Is it because of one’s karma? Kindly clarify.

Sharanagati will fructify. If Sharanagati didn’t fructify for worldly benefits then there may be deficiencies rendered in the components of sharanagati. Moreover, Perumal always takes care of our well-being. We might have performed for some reason and if it had not been for our good, then the sharanagati would not fructify.
We should understand if the sharanagati did not fructify it means the outcome is not favorable for one’s well-being and hence Perumal did not fulfill our wishes.