Obviously it is an academic career credit to be selected as the Editor in Chief of a journal, no matter how humble that journal may be.
And I would tend to say the same for Associate Editor appointments, i.e. those positions with the authority to manage review and make accept/reject decisions.
The role of Editorial Board membership is less obvious. This is a nebulous category for which your name is formally listed but your only responsibility is to promise to do reviews when asked. Probably not even that for some of these gigs. The other "responsibility", I surmise, is simply to lend your name and reputation as a seal of approval to the journal.
This latter is the only reason that makes sense when a list of BSD types appears on the Editorial Board of what is generally regarded as a lowly, but still somewhat respectable, journal in your field.
How many of these Boards should you be on? When you are on zero, then presumably you should take whatever is on offer. But after that? How many? 2? 10?
Is there a point at which Editorial Board participation just looks like ego gratification? Should you gently suggest the EiC ask someone younger, browner and/or female-er?
I happened to be looking over an Editorial Board of a journal recently and was thinking they really could stand to refresh with some younger and less majority-in-science names. Perhaps I shall send the EiC a list of suggestions....