I would argue that in most cases they are too big. Too big to get stuff done. Too big to interact and communicate. Too big to ship releases quickly enough.
Let me give you an example of a company that supports a Weather app that I use - Hello Weather. It is a lesson in how to make great software and how a small group of people can do great work.
How big is Hello Weather? They are just three people. Working part-time, while holding other full-time jobs. Really, is that it? Absolutely.
And what do they support? Quite a lot of development work, that is. An iOS app for the iPhone, an iPad app, support for the Apple Watch and Android and backend interfaces to databases which allow integration of multiple weather source data that can be presented by the app, plus paid offerings with features only for subscribers.
And all this is three developers, part-time? Yes, absolutely, that is exactly what I talked about earlier.
How does it work then? Committed people with common purpose and goals, who are willing to use their creative intelligence to architect, develop, sustain and support this software + solution offering.
If you are having large teams with bus-load of people struggling to deliver software every once in a few months, then there is only one reason for it. Perhaps you just don't know how to do it. (And don't go hiding behind the reason that your organization is special and complex; and it is impossible for all this work done by small teams - my answer is again the same, you just don't know how to do it)
Some of the blog articles worth reading to get more context on their work (Warning, it might shame the work that your teams do):
How we made an iPhone app on the side - (and a few tips to help you do it too) - https://helloweather.com/blog/how-we-made-an-iphone-app-on-the-side
Just keep chipping away at it - Why perfection and speed may not matter as much as you think. - https://helloweather.com/blog/just-keep-chipping-away-at-it
Strategies for building a dual-platform mobile app - Want your app to coexist on iOS and Android? - https://helloweather.com/blog/two-platforms
Always Be Nailing The Basics - Why we skipped adding new features for a while, and improved all the old ones instead - https://helloweather.com/blog/nailing-the-basics
A look inside the weather machine - How we manage 100k requests per day with multiple data providers in real time with autoscaling and fallbacks. - https://helloweather.com/blog/inside-the-weather-machine
Get Your Widge On - https://helloweather.com/blog/hello-widgets
Widget Stack Attack - https://helloweather.com/blog/stackable-widgets