Deskilling effect
The introduction of new, productivity-enhancing technology sometimes enable less-skilled members of the trade to perform nearly as well as its more-skilled members. This may or may not be the intended consequences of the proponents of the new technology. If it is intended, it may bring enormous profits to its proprietors, because the enlargement of candidate pool means the supply of labor is increased, which results in lower wage, and thus brings savings to companies that hire this new technology.
This has been happening ever since the industrial revolution. Please pick up any history-of-science book, or take a short course in a nearby college.
There are a lot of productivity-enhancing technology in web development; there are many client-side and server-side libraries that shorten development time. In some cases it enabled a small team to deliver applications that traditionally would have required a much bigger team.
This is not to imply that web-based or CSS-based program require any less skill in development - the demand for skill simply shift from algorithmic knowledge to visual aesthetics and interaction design, as suggested in MainMa's answer.
Obsolescence
In other cases, the new technology simply made some older, less efficient technology obsolete. Thus, skilled labors who cannot transfer their knowledge to the newer technology will lose their competitive advantage, or even lose their usefulness entirely.
A recent example of obsolescence is desktop software development. It is being gradually replaced by web-based systems. There are great economic advantages in moving to the latter: it shortens the product release cycles from years down to virtually zero.
Structural change
Jobs that are eliminated from deskilling effect or obsolescence, or from global competition, will usually not bounce back to its historical levels.
Knowledge workers
Software development is one of the trades known to require a never-ending, life-long continuous learning effort.
It is possible to identify engaging challenges and rooms for improvements in an otherwise repetitive or passive day job. Perhaps you can learn visual design and electronic commerce in your personal time, and bring more value to your employer. Simply seeing the bigger picture would have helped you find a career path. The imperative is on you to either find a more intellectually challenging job, or to make your current job more interesting.