I love R, but how can you make that claim when R uses three distinct object-oriented systems all at the same time? R might seem stable only because it carries along with it 50 years of history of programming languages (part of it's charm, where else can you see the generic function approach to OOP in a language that's still evolving?)

Finally, as someone who wrote a lot of R pre-tidyverse, I've seen the entire ecosystem radically change over my career.