If the issue of needless assets were merely an issue of summer camp, that would be one thing, but regrettably, that's not the reality. Just for kicks, I thought through the number of attendees versus the size, and cost, of the physical plant.
Some churches did very well. A church I attended in Colorado had about 8000 square feet and about 150-200 consistent attenders, or about 40-55 square feet per person. One I attended in the Twin Cities, sharing space with a day school and seminary, typically used about 50-60,000 square feet and had 600 or so attendees, about 100 square feet per attendee.
On the flip side, one local church with about 50 attendees and 10,000 square feet, about 200 square feet per attendee, and my current church, with about 45000 square feet (my estimate) and 300-400 attendees, about 110 to 150 square feet per attendee. Another church in Waseca typically had about 20 or 30 in attendance and 5000 square feet, or about 200 square feet per attendee.
The same equation goes for land; some churches are more or less on a city block, others have 15-30 acres on their property. For reference, 10 acres is ~435,000 square feet of land, so if one splits the property between parking (5 acres/ 400 cars), building (2.5 acres/100k square feet), and green area (2.5 acres), you've got a nice facility for about 1000 attendees.
In many cases, however, the extra land is going to athletic fields, spare space, and the like. It's nice, but let's be real; it takes a while to mow, is a resource that could be put to other purposes, and quite frankly, many park boards do a much better job of maintaining these fields because they get more usage.
I'd suggest that in many cases, churches have a lot of property that, even with very optimistic growth goals and estimates, they simply will never use well. It's in many ways a waste of money and space.
There is also the question of what all this extra property does to the church. In my view, the end result is that pastors who ought to be "men of the Word and prayer" end up doing things like repairing lawnmowers, administering repair/maintenance efforts, and coordinating big mowing and snowplow crews. I have even seen a fair number of commentary that being able to do this is a key qualification for the pastorate. In the same way, men who ought to be learning to evangelize and make disciples end up....mowing lawns and the like.
Now to be sure, some degree of these tasks will be necessary as long as churches own physical property, but one might infer that churches ought to consider their property in light of reasonable ministry expectations. I love driving my church's new zero turn mower--and I'm getting reasonably good at it--but Matthew 28 simply tells me that I've got bigger things on my agenda.