The simple truth is configuring and integrating current search technologies is a tedious and painstaking process.
Network administrators don’t want the extra burden of setting up, configuring, and maintaining search servers and extra infrastructure.
Development teams don’t want to waste time and dev cycles integrating search…they want to work on the ‘cool’ stuff, their code.
Plus all this isn’t even in ‘real-time’, meaning as new data is added to the system it isn’t searchable until it is ‘indexed’ at a later time…lame.
If you want to scale your traditional solution, cool, just multiply each of the issues above.
So, to answer your question, Search As A Service gets rid of all of those pain points. It lets you and your team focus on your product, no hardware purchases, not setup and configuring, no maintenance, no problems.