The chart used to be bigger with entries like the Ak2i, M3i Zero, DSonei, EZ-Flash Vi, iEvolution, etc... but those carts stopped getting updates/support, so they were dropped off the list. Updates not only mean the ability to play new games, but also the ability to work at all on a DSi/3DS (which have anti-flashcart updates themselves). The list is so small nowadays because the DS is dead, so most of the good teams have simply discontinued their products.
As far as all the fakes and clones... these are Chinese aftermarket goods, so there's a lot more bad-quality products out there than good ones. Especially when it comes to any cart with "R4" in the name, 99% of those are fakes or knockoffs because the original R4 team only made "R4". Any "R4i", "R4 SDHC", or anything else like that was not made by them (and a large majority of them are badly-supported carts). These carts will often give two or three updates, then drop off the face of the planet.
While there are some flash carts that actually try their best to give support and updates (you'll notice an R4-named cart IS in the list), the majority out there will drop support quickly in order to get you to buy a second cart, then a third, then a fourth...
http://gbatemp.net/threads/update-o...d-v2-0-using-akaio-updated-to-3ds-4-3.342339/
http://gbatemp.net/threads/identifying-flashcart-fixing-one-for-my-nephew.341230/
http://gbatemp.net/threads/r4itt-purple-new-sticker-problem-about-adding-games.343271/
http://gbatemp.net/threads/r4i-sdhc-help.342623/
http://gbatemp.net/threads/r4itt.342556/
http://gbatemp.net/threads/software-for-green-r4i-card.316171/
Check out those threads, people bought carts from teams that didn't give support, and so were left with carts that wouldn't play new games, or even work at all on their DSi/3DS. This is why it's so important to pick a product from a site/team that actually attempts to give more than one or two updates, and unfortunately that list has shrunk as teams simply stopped and left.
