Another argument put forward is "feature x is just syntactic sugar, we don't need it". My answer to that is, if you don't like it don't use it!! There are many features in Delphi that I don't like, I just don't use them, but that doesn't mean they should be removed. I have often seen comments about language features where people don't want the c#/java/whatever features polluting their pure pascal code. I have tried to focus on language enhancements that would have zero impact on existing code, i.e. These days I prefer to write less lines of more expressive code. Many of these potential features would help reducing verbosity, which helps with maintainability. I have several abandoned projects on my hard drive that were only abandoned because what I wanted to do required language features that just didn't exist in Delphi, or in some cases, the generics implementation fell short of what was needed.
Some of the features I list below have the potential to spur on the development of other new libraries which can only be a good thing.
Those two language features alone enabled a raft of libraries that were simply not possible before, for example auto mocking (Delphi Mocks, DSharp), dependency injection and advanced collections (Spring4D). Probably the biggest change was the addition of Generics and Anonymous methods. Yes there have been some changes, but they were mostly just tinkering around the edges. The Delphi/Object Pascal language really hasn't changed all that much in the last 20 years. TL DR - The Delphi language is very verbose, dated and unattractive to younger developers.