As we progress in our career and spent too much time at workplace, do you think, we have less time to improvise our skills & working methodologies?

It always boils down to how one prioritizes tasks and manages one's time. If you definitely want to learn new skills, you will find time in spite of your busy work schedules. 

It depends on the job nature and environment of workforce. If your supervisor stay in the organization more time, how is it possible to leave organization specified time of work. I belief organization needs learning and development opportunities inside and outside of the organization. Less time is not to be improving knowledge and skills to perform better in the organization.

It depends on how static or dynamic your work is, and it depends on the environment/employer you work for.Having worked for IBM for17 years at  Aramco in Saudi Arabia, I had two great companies and a very dynamic field with ongoing changes and new things to learn every day.

The environment gave me all chances to grow and enhnace my skills while on board ...

So, in short, no ... I did not personally come across this problem !!

I don't think that way my friends. As Mr. Thaib says, it depends on the nature of the jobs you are performing. Moreover, it depends upon your will my friend, As the old scholars had said "where there is will ther is a way"' it all depends on how thirsty are you.