Even though bitcoin is decentralized, are people still able to develop it and evolve it to compete with other crypto as time goes by?
No technology is perfect from the very beginning, and Bitcoin is not an exception to this rule. "In Bitcoin we trust", some people say, but I personally trust not in Bitcoin itself, but rather in the current team of developers behind it.
Bitcoin Improvement Proposals (BIPs) are being submitted and considered constantly. So, yes, BTC is an evolving organism.
You can learn more about BIPs by following the link below:
https://github.com/bitcoin/bips