"This tends to be a particular problem any time you have a democratic union. Dictatorial unions with little control by rank and file members allow union leaders to ignore the special interests of long seniority employees and negotiate a fair deal for everyone. But the more democratic the union, the more senior employees pig on on benefits at the expense of all other employees, customers and investors."

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Actually, wouldn't a "democratic" union would tend to vote
greater benefits to the majority of the membership - such
that if there were many newer members the union would tend to
emphasize causes that would support the younger members - opposite
if the membership were composed of mainly veteran members.
A union controlled by a "personality" or a "special group"
(e.g. criminals/thugs) would make deals to funnel funds
where the "leadership" wants without regard to the members.

This tends to be the problem mature unions are faced with - the
leadership does not respond to the members or actively steals
from the membership in some circumstances.
Witness the Teamsters of Jimmy Hoffa amongst others.
If done with sufficient finesse, the membership elects the
same leaders even if they are actively harmed by the leadership.

When union membership can withdraw from one union to
join an alternate union organization, there tends to be a greater
tendency for union leadership to develop the capacity to
listen to membership.
Course, this is not an approach favored by most unions - but it has
happened - particularly in some of the service unions.
But union competition - as has been the case with many original
union developments can be discouraged with sufficient baseball
bats or machine guns in sufficient hands.

Pretty much holds true for any organization. The ability to listen
to members, stakeholders, customers tends to improve with
competition.
Lack of competition eventually leads to the "absolute power corrupts"
end seen repeatedly in human history.

Howie52