Discussion on missing optimizations

Hopefully it's alright for me to post this here, please let me know if not.

I ran across an article on blog.jooq.org comparing all the major RDBMS'
with their ability to optimize away unnecessary work with queries which are
less than optimal, and saw some discussion on hackernews and reddit, but I
hadn't seen any discussion here.

The article in question is here:
https://blog.jooq.org/2017/09/28/10-cool-sql-optimisations-that-do-not-depend-on-the-cost-model/

Commercial databases seem to have a serious leg up in this area, and there
are even some that MySQL has that Postgres doesn't.

I was wondering which of these are planned, which have had discussion
before and decided not to support, and which just haven't been thought of?

I thought i'd bring it up and hopefully others who are more knowledgeable
can chime in.