The public guardian may, on the public guardian's own motion or at the request of the court, intervene in a guardianship or conservatorship proceeding if the public guardian or the court considers the intervention to be justified because (1) an appointed guardian or conservator is not fulfilling duties;
(2) the estate is subject to waste as a result of the costs of the guardianship or conservatorship;
(3) a willing and qualified guardian or conservator is not available; or
(4) the best interests of the ward, respondent, protected person, or person who is the subject of a conservatorship proceeding require the intervention.