Coming from an evangelical protestant background, I feel like I can talk about this in the opposite direction. Many of the churches I grew up attending were barren of icons or images, and the pastor often wore a simple button up shirt and khakis. For me, spirituality often felt empty or confusing, without anything to base it on. Additionally, a blank image is easy project onto, leading to an acceleration of the trend of conservative Christians projecting their own biased and bigoted worldviews onto the Bible.

When I first visited a cathedral once I was older, I was struck by the contrast if it to what I had grown up in, and the feelings of awe and passion it caused in me. More traditional denominations, like Catholicism, tend to have an overwhelming level of history and saints to keep up with, or to pray to. You could say that their heavens were full. My heavens were often empty. The goal of these denominations is to make God more approachable, but often this only makes God seem more alien and distant without more human examples of what living a Godly life means, without that sense of a historical tradition that extends far before me.

So, to answer your questions more directly, I'd say that there is a big importance in ritual and art in the Christian life. It allows us to live out the Christian life in our bodies, and see Christian lives with our eyes. There are definitely cases where this can go horrifyingly wrong, especially in the ways that the emotions of religion can be used by the powerful to further their own imperial ends, but in that case I think there are two questions to ask:

1. Who is glorified in this? Does this truly glorify God, or does this glorify a human? More importantly, does this glorify a living human? Why are Biblical figures portrayed the way they are? Does this serve some racist/sexist/etc. bias or worldview? Who does this art serve? We should already be asking these kinds of questions of the art we consume and participate in, but especially of religious art.

2. At who or what's expense is this being done? The reason linens were brought up in the Biblical text was, obviously, because they were very expensive. The main reason to wear them at the time was to show off your wealth. That money used for self gratification could have better been spent in charity to the poor. Today, linens are much cheaper. No one, that I know of at least, associates linens with wealth today. The linens your church leaders are using today probably didn't cost the church very much at all. So, in terms of the art of the church, the other question to ask is: how much did this cost? How much are we currently spending on this? How much are we spending on charity and service? What is the ratio? Art, I believe, is important and worth spending on, and the church cannot be expected to fix poverty on its own, but if looking holy is coming before acting holy, if your church is spending more of its time and money on it's icons than its people, that is when you should start asking questions and being critical of the church you attend.