The ACF taxonomy field stores an array of term ID values, you can’t search based on the term name or use ‘=’ for the comparison.
You need to use the term id and you need to use LIKE, something like this
'search' => '*'.esc_attr( $search ).'*',
'meta_query' => array(
array(
'key' => organization_category,
'value' => '"'.$term->term_id.'"',
'compare' => 'LIKE'
)
).......