Second, pretty much NONE of software patents are useful. Most of them are filed for defensive purposes or to show "value" for investors and are never asserted or licensed. During the recent years 20 years or so the cost of patent litigation exceeded the licensing revenue for software patents ( https://arstechnica.com/inform... ).
Third, there ARE useful patents. Pretty much none of them are purely software ones. A novel agent for extinguishers would be a great invention. However, in software patent speech it would be described as: "An agent consisting of chemical matter that utilizes heat-sensitive decomposition reactions to rapidly terminate the free-radical heat-driven chains reactions", - without any actual chemical structure specified in the patent.