As long as you can keep busy that way it is fine to have those jobs with downtime! The challenge arises when, for example, the workplace doesn’t allow personal cellphones on site or in the work area. Or perhaps there is an expectation to look busy all the time so you don’t have the leisure to read or write. I’ve had the luxury to have a job where I can relax a fair bit and have some enjoyable free time with your pastimes listed above.
My previous job was at a workplace with no useable internet, poor cellular signal, and no phones allowed while working policy. Very strict to always be doing something to look busy but when there is nothing to do it gets dreadful.