Who do you feel should pay for career development training courses?

I think that this depends on the organisation that you belong to. If you are in a professional firm, such as one of the big four, the first would apply for the training that you receive after you join as a graduate.  If you work for government, the workplace may pay. In some organisations additional training for career development is given to high achievers or those with promise, to assist them to grow.  I personally have had training where I needed to stay with the organisation for a year after my training which was paid for by the company. I think that may still happen in some cases, e.g., apprentices.  Entry level positions often give very little training on the job.

Both, workplace may invest for very specific training skills and employee should invest in self-development

Both. workplace and individual
shows but in by both.

It is a combination of all of those things

For very task specific skills the company should pay and it should be on company’s time

If someone in Engineering want to get into Marketing the company should pay but it should be on the employees personal time

Before the tax law changed my company would pay 100% tuition fees and for books for any college degree as long as it could apply to work. They were pretty liberal with it and it really retained employees and also made them more valuable to the company

In later years it dropped to company paying 80%, and then it dropped to 20% or $5,000 which ever was less on an annual basis. Nobody uses it now, or if they do they leave as soon as the required retention is over

I was fortunate to get my masters from the McCormick School of Engineering at Northwestern University. There was no way I could afford or justify it at $5k per year from the company