Photoshop, the designers ‘must-have’ is such a flexible tool that there are many ways to set up your workflow.
After some 20 years I have found these two to be the most efficient, most transferable within a team, and most manageable i.e. avoiding the dreaded spinning-wheel-of-death
Fickle as clients can be, I’ve come to realise that there will always be amendments. Version after version, where the client/stakeholder/CEO wanna-be-designer suggests colours or positioning changes. Simply switching on/off layers and groups and saving as a state was an ingenious ideas by Adobe. Big pat on the back.