Currently writing a novel about a man spiraling downward following a divorce, among other things. I want the reader to be grabbed by this man even though by all accounts he's a bit of an unsavory character (albeit as a result of his issues), I was considering beginning the story in a bar. Showing him within the proverbial pit but I feel like it's just such an overused beginning of stories surrounding similar issues. What is your opinion?
Starting in a bar is 'good' because anything can happen
Starting in a bar is maybe a cliché, but for good reason. No one needs an in-world excuse to be there. The power structures and interpersonal dynamics are quickly understood (and might be different outside the bar). Society-at-large can be represented as a microcosm in the patrons and staff, introducing politics or race/class divisions without story consequences.
Time and place, as well as economic conditions, can be signaled with a minimum of cues (the quality of liquor, the sobriety of the patrons, the music on the jukebox, etc). Specialty bars sometimes serve as de facto community centers for marginalized groups. There's no need to explain why these characters are co-existing at this location.
A reluctant MC doesn't need to chase the conflict. The inciting incident can happen in front of them so it doesn't need to be personal. We can meet a blank-slate protagonist through their actions, without touching their backstory or revealing their status in the world. Likewise, other characters can be introduced without prior connection to the MC.
Starting in a bar is 'bad' – but it can get worse
The MC may think this dive bar is the lowest they can go – they've hit rock bottom – but there are even lower tiers within easy reach. The dive bar's bathroom might be a new horror, or the alleyway. The MC might go home with someone, or try to prolong the bender with drugs at an afterhours. Their anonymous downslide might be exposed in the worst way, ending them in jail or otherwise jeopardizing their normal life.
Negative character arc cues like drinking alone in a dive bar can be excused/reversed because they are having a bad night or just passing through. Interactions with the bars other patrons can quickly give us cues about the MC's inherent morality. They can easily misread a situation with the excuse that they were temporarily incapacitated, or a fish-out-of-water (helping the wrong person, falling for a con, losing their wallet).
If you think it would illustrate who your character is, I'd say go for it. Just twist something up a little bit to separate your story from the others with the same beginning (like don't make what happens in the bar go the same way, give the setting a slight quirk, or something). And if it's just too similar, maybe use a different setting that serves the same purpose. Maybe he drinks at home. Maybe he's wandering the streets after being at the bar. Anything that shows what kind of person he is/what state he is in. Only you can know. Have fun!