Excellent for beginners, straight forward and teach new players.
Mainly because of banner armies teaching new players to use multiple types of units. Might be gimmicky at first, but there is method in there. The most common noob mistake is spamming just one unit(I remember spamming Cuirassiers as a kid). Banner Armies help with that. Otherwise, their economy and other stuff are straightforward, the only problem might be dealing with expensive units and gimmicky housing.
Straightforward, solid economy, simple playstyle, if you are new to WoL or AoE3 in general, go French. They teach the best, whilst also being reliable. Others have some nuicances or gimmicks that can make things tricky, like with the Russian batches or Ottoman settler production. France has none. It is a simple late game beast.
These are my two beginner civs