I'd agree that having different perspectives in the idea phase is very important, but when it comes to implementation, diversity doesn't matter at all. Get the data from database, stick it in the views. It's pure technical ability at this phase.
I went and talked to the customers and other stakeholders, and found out that 300 hours was actually a nice-to-have. 48 hours with some margin was absolutely necessary, and 100 hours was better than equivalent devices on the market. We got buy-in to change the requirements and released the next week with a 100 hour lifetime.
Just an idea what a different perspective can bring.
I'm just responding to your anecdote and I do agree that different perspectives are valuable. My point above was just that there are many, many places to include diversity and the hyper-focus on the implementation phase (aka development) means you will miss the more valuable lifecycle phases where diversity has much more impact.
Some years ago, a Jewish person on a professional forum told an anecdote about some group trying to do outreach to the Jewish community and scheduling their first meeting on the night of some really major Jewish holiday, a holiday so big he compared it to Christmas. Unsurprisingly, no Jews attended this meeting.
When I worked at Aflac, they always said "We hire everyone because we sell to everyone." If you don't have any members of certain demographics on your team, there will be things that just never occur to you that you may never learn you needed to know if you wanted to genuinely serve such people.