They didnt, dont make the mistake of thinking Saas companies are just software companies. They are Sales companies who happen to sell software. Companies like Dropbox & Atlassian have long been surpassed in Tech but they live only because they continue selling even when demand was hard to get. Their moat is sales & networking and software has to be just good enough. And other part is service, these companies still have one of best costumer service since the start of early 2010s. You can still get refund on Uber quite easily, but if you try doing that at a regular old school company you would require a prayer and couple of business weeks.