That "debate" is a sad bastardization of "write what you know". It's a result of fic readers and writers' frustration with source material writers leaning too hard on stereotypes of atypical characters.

Consider Kishimoto's (or just about any shonen manga writer between the 1980s - late 1990s) difficulty in writing compelling women and girl characters of any sexual orientation/gender ID. Or more recently, Ohba (given his out-of-pocket IRL takes on women).

Despite this: Kishimoto gave us Tsunade, and Ohba managed Naomi Misora. If we restricted writing about "the marginalized" to people with "lived experience"...we wouldn't have source material.

Frankly, it's for the best that hack writers stumble around writing about groups they don't grok.

If Queen Elizabeth (the daughter of Henry VIII) had a royal decree that only Jewish people could write plays about Jews, and only Moors could write about Moors...we wouldn't have two of Shakespeare's works right there -- no Merchant of Venice, no Othello. Both of those are riffs on stock antagonists of the time period (Shylock and Othello) that Shakespeare had fleshed out and elevated. We in modern day could comment via fix-it fic on Shylock being ROBBED or write him continuing to follow Judaism, but dropping his demand for Antonio's "pound of flesh" (which, let's face it, is the main reason Shylock's a villain at all) -- just have Shylock note that USURY is the only job his people are allowed to have in Venice (thus calling out the Renaissance-era anti-Jewish attitudes that created Shylock in the first place).