Yes, I think riches are a proxy concept for “attachments”. In this case the economic wealth is used as a proxy to represent “possessions” but not economic/physical possessions. These “possessions” are beliefs or preconceived notions.

This eye of the needle teaching echoes the teaching of the empty tea cup koan from the Zen tradition.

If we are unwilling to let go of what we hold, we may be preventing ourselves from holding onto something better in the future.