Charity shops actually get pretty decent footfall at least in my experience (but maybe that's just where I live). More than that they have a few structural advantages other than tax breaks which means they are able to compete where traditional retail can't - things like low staffing costs (if they use volunteers), no/very low inventory cost, and they are usually able/willing to sign up to lease terms which more commercial enterprises would either struggle to secure, or would be unable to live with (eg almost no security of tenure).