Racks and panniers are not as practical to keep with you when going to a store or stoping for lunch, plus you also would be carrying extra weight of the rack, bike racks have their own problems, fasteners come loose even on good quality ones, they get in the way of attaching a trailer if they are rear racks, they also get in the way of Fenders if you like the rain protection of tire fenders, etc. Racks and panniers and Trailers all they have their benefits, I use my trailer carrying my recyclables to recycling center weekly, I use racks and panniers for my grocery runs, for commuting and touring I just get on my fastest bicycle with just a lightly loaded small back pack and I go,