At this point, humanity has partially conquered evolution. You can choose a different purpose than reproduction or fitness of the human species (helping others, as you put it).
There are people who see helping animals and nature as more important than helping other humans.
There are yet more who strive primarily for their own personal wealth/power, to the detriment of mankind and only sometimes with their own progeny in mind.
With that in mind, I think you may wish to also be more specific in your stated purpose. "Help others do their thing" is vague and imprecise. It would allow you equally to use your time and money to support others who's goals are merely to get rich (say, to be an angel investor), and to help others who's goal is likewise to help others (help others improve their lives and better themselves, such as through working at / giving to foodbanks, helping those doing positive work for humanity, etc).
I charitably will read your meaning not to be "help others to do their thing", but rather to "try to have as positive as possible an impact overall, including through helping others". If helping others is done with the intent of having a positive impact, it looks much different. You don't become a VC (the 3rd most evil profession) that optimizes for maximum returns, but instead help fund interests that you genuinely believe will end up being overall positive. You don't help others do their thing unless, as best you can tell, their thing will also have a positive impact on others.
Did you mean something to that effect, or do you see your purpose truly as an amoral helper who wishes to help others but neither impact good yourself (directly nor indirectly), nor discriminate in what "others" and "things" to help?