That can't be true. If you spent all of your time developing new skills you wouldn't have any time to capitalize on them. You are likely better off conquering a niche.

This but keep in mind that "selling our skills" is also a skill of its own.

No, it's not.One won't enter the market today,as it'd take 6-12 month to get to the point where you know the basics. Such a person wouldn't be competing with those from Uber,as the level of seniority is completely different. 100% junior dev jobs may be hard to come across over the upcoming months, however there are tons of jobs out there that would absolutely benefit from having someone who can write even basic scripts.