While the actual individual LED on an LED wall may last 10-20 years, based on the 100,000-hour maximum when looking at all the parts, and not just the LEDs some panels can be expected to have failures much sooner.
With the upgrade to 720p, then to 1080p, and now 4K and beyond that makes for far greater detail to be shown to your audience. This leads to the need for greater detail being paid to what you are capturing.
Depending on the needs for your house of worship space, either type of projector works better for different types of installations, beginning with whether the projector is being used for long periods of time, or occasionally.
For video to be an effective, natural part of the experience you're creating for your audience, you must find the delicate balance of placing them where they can effectively support what is happening in your service.