Is Bitcoin (and likewise Bitcoin Cash)the only truly decentralized cryptocurrency? It appears that all the other altcoins are connected to companies or individuals who control them.
There are many decentralized currencies, you can take a look here:
Not all coins are connected to a company, the main big ones that are connected to a company are Ripple and Factom. Other coins might just have foundations that is responsible for marketing and other related matters, but they do not control the coin itself as the miners and coin holders do.