The tasteless ones are probably invasive mock strawberries from Asia, which are edible but not very good. They're the same ones that are in my yard. Supposedly they grow in basically the same environments as the native strawberries used to and have been outcompeting them in lawn/weed enviroments; the native Fragarias have fruit about the same size but much tastier. (My mom remembers eating them before the mock strawberries took over.) I would love to get rid of the mock strawberries and replace them with Virginia strawberries but I have no idea where I would even get any, to start with - the domestic culivars I've seen are all bred for huge fruit and thus want sunlight.