This is not a question that can be answered in a definitive way. It all depends on the person in question. Let me give you some perspectives.
First, if technology takes away time from important things like reading and writing, then it can make people worse writers, because they dedicate less time to it. For example, some people are too into video games. For this reason, they may never write. Others use technology to surf the Internet endlessly and in the process read things that are not very good. This waste of time will make a writer worse.
Second, there are those that use technology in a wiser way. They use it to get information in a quick way and the like. I would say that for these people, technology makes them into better writers.
In the end, it all depends on the person in view.