I'm not sure what do you mean by "Maybe, this is hampering my learning and performance ability as I take my own time to learn things." Isn't learning on your own supposed to enhance your learning ability?
Personally I think if you have interests for diverse things just follow your interest and go for it. Generally, intellectually serious, industrious and inquisitive guys will naturally have a wide range of intellectual interest and this is only natural. I've seen a lot of wonderful people who look almost non-human because they do so many things well at the same time, bettering the majority of others in each of them. On the contrary, I've seen some others who say they are "focusing" on their main area and not "wasting time" on the rest, while in fact they are too burned out, tense and close-minded and really aren't "masters" of their trade, even worse than the prior type of people.
I don't know how you define "ROI". It can be a very broad concept. Following diverse interests will probably make your life happier and more rewarding, which is already a huge return in itself(You might even feel your life incomplete with those pursuits). If you're talking about advancing your career, notice that people draw inspirations and ideas from their knowledge and experiences in other seemingly totally unrelated fields and achieve surprising success thanks to a new perspective.
In short, you should be thankful that you are among the type of people that have the passion and intellectual curiosity to learn more and know more. They almost always do great in their lives.
(Examples that immediately leap to my mind:)
- Steve Jobs applied his knowledge of calligraphy to Apple, this we all know
- Paul Graham, founder of YCombinator, studied CS and serious drawing at Italy at the same time
- Jeffrey E. F. Friedl, the author of Mastering Regular Expressions, is an avid photographer and speaks fluent Japanese
- I know a friend who once worked in consulting, investment banking, NGO etc, but then decided to be a commercial pilot and succeeded
Also you can refer to this hugely upvoted answer on programmers SE, which advocates explicitly for a "jack-of-all-trades".(Although I would say he's a little bit too extreme)
Of course, while doing all of them, ensure your mastery/focus in your profession. Otherwise it looks like procrastination rather than real learning. Also, to "be master of all trade but jack of none" is basically improbable so don't let it burden you. But it's not hard to be a master in several trades.