
The reason I don't know for sure is I never really watched it. I tried to because I quite like Matthew Rhys. But the pilot movie seemed more Bogart than Mason to me, so I gave up. My information here is based on summaries of the show.
I suspect that having Della Street be a lesbian in the 2020 remake was partly to explain why she and Mason never get together and possibly, also, a tribute to Raymond Burr who was gay and lived with a partner for many years on his ranch.
But I find the choice somewhat disappointing and the reason has nothing to do with characters being or not being gay.
The reason is that the unstated romance between Della Street and Perry Mason in the original 1957-1966 show (where they are a kind of low-key version of Mulder and Scully) was WAY ahead of its time.
Unlike so many of these shows--in which the detective or PI or hero figure rushes around rescuing the poor lil' woman-- Perry treats Della with an impressive degree of "hey, you can handle yourself" respect--even in the later movie where he defends her--and she responds in kind.
In an Season 6 episode, Della is worried about a friend. She asks Perry how far he would go for a friend; he is emphatic that if he trusted the friend, he would do whatever he could to help. Della then asks Perry for a loan of a substantial amount of money. He pulls out his checkbook without hesitation and gives her what she needs.He doesn't try to force her confidence. He doesn't try to fix the situation without her consent (though he later, of course, defends the friend in a trial). He utterly trusts her assessment of the situation.
The behavior is still impressive if Perry is helping Della, his friend. But Perry helping Della his friend, secretary, and woman-he-feels-romantic-towards, the behavior is...once again...WAY ahead of its time, an exemplar for every kind of couple relationship.














