You're mistaking the role of a mature company. Unlike a startup, in a mature company there are a ton of customers relying on your product and making sure you don't f*k up their business with a mistake or careless change is much more important than building cool new stuff quickly. You don't want your bank "moving fast and breaking things". There are a whole lot of industries where stability and consistency are an order of magnitude more important than fast innovation. This may not be as sexy or fun as rapidly prototyping some MVP, but it's how a lot of important stuff that runs the world works. To this end, a large org may not be everyone's cup of tea.
Yes, there will be some waste and bureaucracy at any large org, but that's not the same as a place full of people "that are okay getting nothing useful done". If anything, it's the established boring companies that are doing something useful (even if that something is not sexy or exciting), while a lot of startups are just burning through someone else's money designing things that no one really wants or needs.