Epoxies used today in The aerospace industry have been developed for just that - aerospace. With huge temperature changes and strength to weight demands, today's aerospace epoxy offer more solutions than ever before. Are they cheap? No. Do they require special handling and curing techniques? Usually they do. Can you get samples from manufacturers? If you ask nicely. Will it withstand the temperatures I want? Just read the data sheet supplied with each adhesive, some will, some won't.
People continue to perpetuated the misinformation that epoxies and other adhesives are inferior to welding and braising while due to advances in technology within the last 20years the opposite is actually true.
Adhesives offer more control and even more flexibility when used for the proper application - just look at the euro fighter. It's not welded together.