I have been to kastners during the height of the snowbird season. Yes it gets crowded, but I’ll suffer with the crowding to support a jewish business owner.
People see all too willing to forgoe the local jewish merchant for the larger chain stores etc.. But let me ask you a question. Who do you think contributes more to Jewish causes? Are the owners of publix making contributions to local tzedoka’s? Maybe they donate food for tomchei shabbos or are giving free items to local frum people who couldn’t otherwise afford to make shabbos.