It is as of yet unclear if software will reach that long term profitability. Video games certainly can have it though. I've purchased copies of games which were coded before I was born. Tech is still a young and growing industry where we find new use cases every day. As this slows and as software is perfected this may change. If someone designs the perfect email app it may just be able to run in steady state for decades. We haven't seen that but it may be a reality at some point in the next two decades.