I think the aesthetics of a Church are important. Aesthetics have meaning. If you walk into a Catholic Church, you are surrounded by meaningful iconography. It's not there just because of "muh tradition". It's there to convey meaning to the believers who walk through those doors. The tall ceilings draw your eyes up and make you feel small. The statues and paintings of Saints are there to give you a relatable face for a rolemodel of some virtue you should want to be like. The hymns and the rituals are to ingrain important ideas in your mind. I'd say that aesthetics is one of the reasons why Catholicism has a higher retention rate of Christians than Protestantism.
A Church that looks like a Cathedral or an old Church house is immediately identifiable, whereas a Church that just looks like another non-descript, brutalist modern building just blends in. God doesn't call us to blend in; he calls us to stand out.
Protestant aesthetics tends to imitate the world (ie, Christian rock). There is a drive in Protestant Churches to strip iconography out. Empty crosses without Christ on it. We should have a connection with Christ's suffering, and seeing that is viscerally effective. Jesus said take up the cross and follow him. The Cross has always been a symbol. Aesthetics have meaning. The Protestant argument is that only the words matter.
Firstly, the use of just the cross without Christ on it to represent Christianity long, LONG predates the Catholic/Protestant Schism. That Protestants prefer to use the Cross over the Crucifix as a symbol seems to be a really petty point of argumentation.
Secondly, as I pointed out, the vast majority of Protestant chuches DO follow a clearly visible traditional patterns. They often look like this:
Or this:
Now, yes, many Protestant Churches lack as many fancy amenities, like stained glass windows and the like, but in large part that has to do with the fact they are smaller congregations that cannot afford things like that and so focus on what is necessary for worship and teaching.
As to Megachurches that end up with large buildings, firstly, I don't think there's a single Church in the US that uses Brutalist Architecture. I understand that Brutalism is a hated for of architecture, and it is terrible, but it IS a SPECIFIC thing.
This:
Is not timeless, it is not that aesthetically appealing to me, nor does it entirely indicate a Church to me, but it is also NOT Brutalist.
This is perhaps even worse:
But again, this is not Brutalist. It's terrible and looks like a generic conference hall, but again, it's not Brutalist.
This is a Brutalist Church:
Or this:
Or this:
There are others around the world, but they look nothing like the generic meeting hall style of Churches I posted above.
All that said, I agree that aesthetics are important, however, what is most important is for a Church to provide a place for Christians to gather in Christ's name and offer teaching and worship that is orthodox and brings glory to God. None of those things REQUIRE a certain aesthetic, a person's home can serve as a Church (and historically often has, from the time of the early church when it was under persecution to today in where the Church sees persecution). Are those somehow less churches because they are, quite literally, generic homes?
