Earlier quoted context omitted.
They will never catch up because Google is the only one dedicating enough engineering to match the growing amount of information, and their level of effort sets the pace of increasingly high user expectations for search results.
There is a growing sentiment, mine included, that Google search isn't getting better. In fact, I feel it's markedly worse for many queries. The problem for me are all the blogspams out there. These -should- be easy to just punt, but alas, they do not. I'd gladly switch to any search that didn't show me such results.
An insightful breakthrough in quality that vastly reduces the computing and engineering required to serve great results that keep up with expanding information, similar to what Google did for search 20 years ago, would be wonderful, but it won’t come from DDG or Brave unless they can develop new models that completely replace their current search products.