I was just thinking a similar question: Why are there so many restaurants in our neighborhood? Shouldn’t there just be one place to go eat? I have counted a dozen on one street!
Would we be better off with just one big restaurant? I don’t think foodies would agree. Some love Thai, others prefer Italian. The formal dining experience in one place suits some, while others seek a casual night out. Family friendly fast food joints will not attract the fine diners, and fancy plates with a tiny little gourmet morsel in the middle will not be popular with hungry adolescents. Vegans don’t seem to enjoy steak houses. Carnivores don’t always go for quinoa burgers.
The wide choice of restaurants caters to all the varied tastes and moods. There can’t be a one-size-fits-all eatery.
It’s the same with synagogues. Each one presents Yiddishkeit with a different taste and unique angle. There are Sephardi and Ashkenazi variants, shuls that sing and shuls that don’t, informal and intimate communal synagogues and grand pompous ones, kid friendly and mature audience only. Long sermon, short sermon, no sermon. Every community style fills a niche and attracts different souls. Each custom has its customers. This is not factionalism or doubling resources. It is opening doors and giving options.
The Jewish people are made up of twelve tribes. Each had their own slightly different way of praying, and yet we are all one People with one common Torah. Even the Temple in Jerusalem had twelve different gates for each tribe to enter in their own way. But everyone ended up in the same Holy Temple. Every shul, with its unique style, is a gateway to that Temple.
Rabbi Menachem Mendel Bluming and Rabbi Moss
PS. The answer above applies to sizable communities with a critical mass that can sustain many shuls. Smaller communities may not have that luxury. Either way, when we are committed to Torah observance and Jewish unity, we can pray all together or in our own communities and remain one people.