It would depend on the location.
I worked in one location that did not have them and "all" the other banks in the area did. We were the target of most of the robberys.
I also worked in an branch that was in an office building and did not need them.
It should never be a "marketing" decision but a risk based operations call. I could not see some of the marketing types last a few hours in some of branches even if there was glass.
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Opinions can be considered as coming from anywhere but my employer.
CAMS