The question is typically described as “the historicity of Jesus”. https://en.wikipedia.org/wiki/Historicity_of_Jesus
There are similar debates for other famous ancient figures.
The general academic consensus on Jesus (and many similar figures) is that they did exist and many of the details have been fictionalized.
The former richest man in the world gave away much of his fortune and continues to do so. https://en.wikipedia.org/wiki/Warren_Buffett#Wealth_and_philanthropy
Bruce Wayne is not like that at all though. He’s in a position where he could actually do something about the problems of Gotham City and decides to go LARPing instead.
To be fair, he beats up a bunch of rich criminals too but he whole thing is really more about his ego than about doing good.