Specialization is not a one-size-fits-all panacea. Some generalists thrive on being jacks-of-all-trades and having a variety of tasks on their plate. These workers enjoy constantly learning new jobs and the flexibility of working in several roles, and may grow restless if you trap them in one job. The biggest concern some workers may have about specializing in one job is job security. They wonder what might happen if their area of specialty becomes obsolete. Staying abreast of the newest technologies will keep your company innovative and ensure your workers' specialties will not disappear in your business or the marketplace.
Source: https://bizfluent.com/info-8083551-job-specialization.html