Give people a firehouse of events or deltas, though, and if they want to query it, performance is now their problem - they build the database, update it, index it, etc.
This is part of scaling organisationally, not just removing the database as a bottleneck.
Events are also a route to making cache invalidation - one of the hardest problems in CS, as we know - tractable. Build your caches as services that consume the firehouse, and invalidate based on a join between events and the cached data.
[1] https://en.m.wikipedia.org/wiki/Principal%E2%80%93agent_prob...