All modern printer drivers uses protocols which can be routed, print jobs can either be sent to print servers or directly to the printers themselves. Therefore position in the network from a reachability perspective is not an issue.
You could argue that by placing the printers in a separate VLAN, it is easy to control what devices can reach them, ie. ACLs permitting access only from printer servers.
One of the defining uses of VLANs was to separate corporate functions, so workstations vs printers is one such example.