McG50.
A reasonable degree (of any sort) will give a foundation on which to build further knowledge and expertise, and to learn more advanced techniques. This development process should go on for life. A Degree (or any other qualification) is just a starting point of professional development, not the end point.
There is no reason a person without a degree can't learn techniques, but that would depend very much on the complexity of the techniques, and the ability of that person to learn in a work environment where the emphasis is to get the immediate job done quickly. For example, optimisation is best learned though a set of structured university courses rather than dabbling in canned software while working full time.
theme drift..... time for me to sign off and have another red.