It really varies from troop to troop. Ours is old-school, by the book, multiple leadership positions required for half-year terms. No one got an Eagle who was under 15 and the projects are very involved with construction or logistics. Tearing down and rebuilding a long wooden fence at a women's shelter, constructing display cabinets at a nature center, working with a local charity to collect hundreds of food boxes. Someone built a real footbridge over a stream, which not only required decent carpentry skills but also driving rebar through 8x8 posts into the stony bank with sledgehammers. I got poison ivy twice while clearing brush to make a nature trail and rebuild a garden at a local temple.
These projects are often the first time many youths have ever picked up a power tool or project managed anything.
The bureaucracy associated with the service project and application was stunning.