Video & Photo & Audio Analysis. Why isn't this working?

The PG film was more than likely the one to start a trend of trying to capture bigfoot on film. In photographs and on audio tape. We have evolved to understand more input from researchers and of course, welcome the advancement of technology to give us cutting edge clarity and access to things that were once never available to us. Even our cell phones have the ability to capture video, and in some cases, in Hi-Def. Why is it then that media we have seen is so inconclusive, grainy, fuzzy, questionable, yet in some cases, described by those who have examined it as a bigfoot, further moving forward to explain all the parts of the media, sometimes with questionable theories and science. Even when we have the latest in thermal technology, images presented are far from what we might expect. How do we take this media and where do we go with it? Why is it, after all these years, there remains yet to be a clear and accurate representation of what we are looking for.