Faster search crawls
According to microsoft the latency in the search index can be anything from 15 minute to 6 hours. This is not viable for building solutions that rely heavily on search. http://support.microsoft.com/kb/2008449
In terms of communications planning, these delays create true business issues. When planning major announcements, the communication sequence is planned very precisely. A delay in the latency in the search index and the whole sequence falls apart. In an executive point of view, hard to explain when dealing with business critical announcements.
Gunnar LIed commented
For SharePoint on-premises it is possible to control the crawl schedules with continuous crawls down to 1-2 minutes. Can you give back control on this to admins in O365 as well? It is not very impressive in 2018 even with the most optimistic 15 minutes delay. Real continuous crawling triggered by changed-events with minimum delay should be the target here. When you add news capabilities, communication sites, news roll-ups in Hub sites, people expect a more frequent refresh of content than what you can provide currently in O365.
I've got files that aren't showing DAYS later and Microsoft claims this is normal behaviour, absolutely BRUTAL for an online service focused on file management.