It is still a great learning exercise IMO. Knowing which features are good/familiar to use, but difficult to implement, lets you explore other avenues, like news_to_me and the backslash for lambda [1].
For me, for example, I was gonna go with async/await in my toy language, but didn't like the implementation and decided to explore a monad-like direction.
[1] https://news.ycombinator.com/item?id=38851863
