Membership in labor unions has declined in recent years because of decreased number of?

Membership in labor unions has declined in recent years due to a decreased number of manufacturing jobs and the rise of gig and freelance work, which often lack union representation. Additionally, changes in labor laws and policies, along with a shift towards more service-oriented industries, have made it challenging for unions to organize and retain members. Anti-union sentiment and efforts by some employers to discourage unionization have also contributed to this trend.