Roughly 6.5%, going on some necessarily vague figures (how do you define 'white'?) and some assumptions (proportion of self defined gay/bi individuals worldwide being roughly equal to the UK). In a cast of 8, that's 0.48 people should be straight and white to represent the world population as is. If we include Doug Jones as straight and white (the actor is white and the character is, as far as we know, straight), they are over-represented. If we exclude alien characters from the mix (which also deletes Worf, B'Elanna, Guinan and Tuvok from Trek's already spotty history of diversity) , it is only 0.42 people needed, and so having zero is not far off representative.
I'm going to address your question assuming you are being, if you'll pardon the expression, straight, and not trolling for a reaction. Star Trek has had a huge number of straight male characters, and exists in a TV environment where the default character is straight, white and male. There has to be a reason to have a woman, or a black guy. You never have a reason to cast a white dude. We are represented everywhere. To a degree that we never even have to think about it, because it's unavoidable. We are the hero, the romantic lead, the action man, the nerd, the villain, even half the time we are the gay or disabled character too. There's not one role out there I can't think of someone who looks like me fulfilling. Western culture is soaked in representation of straight white maleness, and a particular form of it at that. That it is so strange when it is absent is really indicative of how pervasive it really is.
So on the rare occasions you get a show without straight white male leads, like Discovery s3, or The Good Fight, it really isn't a problem that needs fixing. We've been playing since the match began and it is very much our turn to be benched.