Correct me, but if two people create a SAAS that can replace a 50 people SAAS, compete on price and the competitor is forced out of the market, wouldn’t this show up as an reduction in GDP? Efficiency (GDP/time_worked) should be up though, and AFAIK it isn’t.
Yes, when prices of goods and services go down so will GDP. I've not seen evidence of the prices of SaaS going down in the past few years.
2 people are now producing what took 50 people previously.
What are the 48 other people doing now? Presumably some other economic activity.