Whether or not to use present tense is ultimately a stylistic choice. Despite what I say below, there is nothing that a gifted writer can do in one tense that they can’t accomplish in another.

The present tense is often said to add “immediacy”, a sense of being in the narrator’s present moment , like a movie. This can help to keep the reader on the edge of their seat.

Younger readers, brought up reading novels like The Hunger Games, may come to expect the present as the normal tense for writing. Older readers, brought up on a tradition that used to favour past tense, may find the present tense irritating or contrived. An analysis of submissions to #pitchwars found use of the present tense was more common in YA writing.

For those who think the use of present tense is an annoying modern fashion, it’s worth remembering that Charles Dickens Bleak House, published in 1852, is written in present tense.  Neither past nor present tense are inherently right or wrong. But there are consequences to the choice of present tense:

• Apart from flashbacks, the use of present tense constrains you to follow the flow of events. This need not be a problem but structures that play with time become harder or impossible. You’re prevented from anticipating and making use of the future (since you’re carried along on the stream of the present) and it’s more difficult to make use of non-linear time, breaking up the sequence of events. The inability to manipulate time can lead to characters who are simpler than they need to be, because the reader has less sense of the past which determines choices and actions in the present. HOWEVER, like all writing strictures, a gifted author need not be limited by this, as shown by the discussion of Sally Rooney’s writing below.
• Creating suspense becomes more difficult, because the narration can’t take into account things that have not yet happened or are outside of the characters’ current awareness. The “little did he know” device is unavailable.
• Unless you’re careful, you can feel forced to overload the present moment with trivial events and sensations that have no real bearing on the story, just because such events would happen in the natural flow of time.

I would suggest that, apart from impulses of fashion, you let your characters’ situation determine the choice of tense.

• Does your character live in the present moment? Joyce Carey’s novel Mr Johnson is written in the present tense because the central character lives in the present moment.
• Does the past fill the present for your character? Have you ever noticed historians have a habit of talking about the past in the present tense? (“Churchill is now facing his defining moment as Germany prepares for invasion.”) If the past fills the present for your character in this way, then present tense may suit you.  Matt Bell talks about the reflective present tense, as being “the way in which memory and trauma often work.”
• Are you using an unreliable narrator? Unreliable narrators deny the reader full information by reporting incorrectly or missing out key details. Present tense can work well here and intensify the surprise when the truth is revealed.
• Are reflection and insight important aspects of your story? Past tense may be better suited here because it allows the story to be told from the distance of time.
• Does your character have a complex and important backstory? To avoid lots of jumpy flashbacks, past tense may provide a better choice.

And yet. Sally Rooney explained in a 2019 interview that her choice of present tense was driven by a grammatical preference: her characters’ frequent reflections on the past would have had to be written in past perfect if she’d been writing in past tense. and she found past perfect ugly.

He feels his ears get hot. She’s probably just being glib and not suggestive, but if she is being suggestive it’s only to degrade him by association, since she is considered an object of disgust. She wears ugly thick-soled shoes and doesn’t put makeup on her face. People have said she doesn’t shave her legs or anything.  Connell once heard that she spilled chocolate ice cream on herself in the school lunchroom, and she went to the girls’ bathrooms and took her blouse off to wash it in the sink.

Sally Rooney, Normal People