When I'm trying to figure out whether to use first-person or third -- and I've never articulated this before -- one of the main things to consider is humor. First is always going to feel more intimate. I always want to lean into that intimacy -- sometimes voice alone will carry an entire novel for the writer because you're not writing as much as transcribing. But if it's a drama or psychological thriller or dark and you can't afford tonal shifts -- especially maybe if you're in the realm of sci-fi where it's always a harder sell -- then first person can really work against you. Or me. I should say that in first-person I always allow my characters to have a sense of humor -- if nothing else than a realistic coping mechanism and how I personally process -- and it can really high-jack a scene. I'm not saying that humor is bad in horror or thrillers or drama. The opposite. It's necessary -- for realism and, when used the right way, it's a great counterpoint and it can make the scene even darker. But it can also fight you line by line, letting the reader off the hook, letting air out of the scene. One way to ease the effect is to go more retrospective. Past-tense and widen the time gap. This allows for a little softening of the lens, nostalgia, less flattening of the scene and more control of how its being read because of meddling from the narrator who has a stronger vantage point.
The longer I've been writing the harder it is to choose point of view and tense -- well, for some projects. Some novels arrive with their point of view stitched into the DNA. This hard decision-making has come as a real surprise to me because most decisions come easier now; I can see more paths through the jungle. But this being able to see, this clarity through more experience, has also made my brain more agile and I can also see the pros and cons of points of view and tense lining up in all directions. I have some rules I've made for myself -- having learned the hard way. But I still flip around with these things, over and over.
For example, Pressia in The Pure Trilogy couldn't have a first-person point of view because the coping mechanisms for a doll-head fused to your fist were too comedic. Of course, as the novel actually took shape, it had to be third because of the breadth of characters who had their own points of view.