You guys quit worrying about nothing!
I have a "relic" fleet in addition to our 3D birds.......
I have a Brishagella Skybolt going through a re-cover (25 years old), a Little Toot biplane (24 years old), a Great Planes Pitts (Got it when they first came out, 5 or 6 years old?) and an old Ringmaster control liner (Bought the kit in the PX @ Orly AFB Paris, France in 1959 and built it about 1963!) The Skybolt had great glue joints. The Toot is in pretty good shape. (I do have it hanging in a local hobby shop for sale but I could stuff a radio back in it and go fly it tomorrow.) The Pitts is still a daily flier and would be the biggest question mark due to it being an ARF. The Ringmaster was built using Ambroid glue and I fly it once a year just for grins. If you snif the area where the pushrod exits the wing you get that "old fashion Ambroid smell" from within. I realize these planes don't go through the rigors of 3D flight but they do get stressed pretty good.
If somebody spent the bucks on a Carden kit and did a fair job putting it together, you can bet on it that a bird with 5 to 7 years of age is still going to hang in there for a long time to come. I'm guessing that the only limitation to all of our airframes is probably gonna be if we dumb-thumb one into the ground or not!
WT