Yea, I think the "base" requirement nowadays to stay in business is mediocre drinkable beer with other options (spiked seltzers/wine/cider) for the non-beer crowd that tags along with the beer nerds.
The other things influence whether you thrive or just scrape by. Definitely need people in your venture with business and marketing savvy. I have a family member working their way into the brewing industry who has now worked at 3 different breweries. The range of business/management/marketing ability by owners/managers is quite wide. Some breweries are a labor of love and scraped together more of a part-time "turn a hobby into a business". Others come out of the gate with a well-designed business plan and a ton of capital investment.
Random musings:
Stony Creek has some of the most "meh" beer in CT but a great brewery vibe, and a fairly dense population (I-95 corridor) to draw from, and huge capital support. Still doing well, as far as I know.
Tox brews some of the best beers in the state, but their original location was just kinda "OK". But they tapped into the higher-volume brewing & distribution model for their core beers through the Twelve Percent contract brewing folks. I'm guessing lots of grocery-store and package-store bought "Fugu" helped support their move into their new brewery (which I still need to go down and visit).
Paddle Creek (now closed) brewed pretty good beer but opened in a pretty "meh" location (north part of East Hartford) that was just not a real big draw for folks to visit.
Norbrook is in the middle of nowhere but is thriving. They brew "good" to "very good" beers. But the place is an absolute destination for a day trip. Amazing mountain biking trail network, great disc golf course, hiking through fields/woods. Animals for the kids to go check out. They have a regular "Car Show" night that draws a ton of people from that social niche. The showshoeing through the woods is phenomenal and they always get more snow than any part of the state given their location and elevation.
Dudleytown (in Windsor) did a great job coming out of the gate with clear huge investments in the space/layout and a cool CT-centric theme (If you've never heard of Dudleytown, check out
The Curse of Dudleytown - US Ghost Adventures
They brew very good beer. They picked a spot that, on first look, may be a "meh" spot on Day Hill Road (basically an Industrial Park road). But, they are literally right next to FastPitch Nation, a destination spot for Softball tournaments in New England. They also have a dome for year-round club sports, That area is a thriving metropolis of hungry and thirsty parents who have been out in the elements all day watching kids play softball all day throughout the sping/summer/fall.