Benefits of systemd over daemontools for services management in Linux

systemd generally has a wider array of options for manipulating the execution environment than daemontools or most of its derivatives do, possibly barring nosh. Though, one could use tools from packages such as util-linux to make up for plenty of it.

Using an init system means you get a more complete framework for managing system state, as the process of booting, configuring early minutiae like TTY and environment setup, shutting down and maintaining service groups in the form of runlevels/milestones/targets are handled.

systemd is a rather exceptional case as it's a project which aims to enforce standard policies and tools for just about the entire layer of low-level userspace. So you will be incurring significant workflow changes beyond supervising processes.

Depends on how far your needs go.