Why do some people still use emission planes instead of area lights?

I’ve been exploring old (and not-so-old) scene files from blendswap.com and I notice many of them use planes with emission materials for their lighting instead of actual light objects. Can anyone tell me why?

Also is it ever useful to put an HDRI file on an emission plane and use it as a light instead of or in addition to the global world hdri light?

Could be misremembering this, but if I recall, when Cycles first came out, not all lamps really worked that great. They would cause lots of noise and artefacts etc…so people used emission planes instead as it was cleaner.

Again, though, could just be making that up lol

That does not explain why recent files are also using emission planes in scenes where you’re not going to see the plane in any reflections.

Do area lights work with textures? I never use them because I am used to using light planes.
What are the advantages of area lights?

Light objects have some optimizations, especially with branched path tracing.

Does it matter if you scale an area light versus using its size property?