Two stroke reeds are not delicate at all. They take a major amount of abuse since they open and close with every stroke of your engine. Think about an average two stroke RPM say around 5K and you get the picture.
Simply put, a reed valve on a two stroke opens on the upstroke to let fuel/air into the cylinder and closes and seals on the down stroke when the fuel mixture ignites.
Two stroke reeds are a maintenance item, that most forget about until their engine sucks a reed and does not run correctly. Symptoms are overall poor engine performance, hard starting, etc. Basically it will run but it depends on how much the reed cage is sealing in its damaged state.
Aftermarket reed manufacturers are ubiquitous and market all types of benefits. Reeds also help atomize the fuel ,and aftermarket reeds have some claim around making that process better. Also, material is often carbon fiber on aftermarket reeds, although OEM manufacturers also use carbon fiber stock nowadays.
Biggest issues for the DIY who is dangerous with a screwdriver in his hands is not installing the cage screws that hold the reed valves in correctly. The screw lets go, bounces around your combustion chamber and cylinder, and carnage ensues. Word to the wise.
Four stroke engines and their valve trains are so different they are really not analogous at all to a two stroke other then the opening and closing during the combustion process.