In today's world, it is not difficult, if they make me their CEO, I will be able to do so.
People who have funds have no idea, people who have ideas have no funds. Thats truth.
It's simply because things aren't as easy as you think. Not because they have the funds that it automatically means that these companies' CEOs can just go "hEy GuYs LeTs JuSt BuiLd a NeW PaYpAL LUL" and compete against the other giants just because they can. I mean, the CEOs of these companies are some of the smartest and most talented people in Silicon Valley. If it was as easy as you thought, they would've built them already.
I do wonder on what would be your face looks like when you are on the actual situation on thinking off to build something with just a single thought in mind and implementing right away?
Agree though that people who do had the better idea doesnt really have the funds but i dont really believe that those people that do had the funds didnt consider or havent those thinking on making one.
They know that they can build something even more which is an add up into their current service but to maintain on having multiple will really be not easy as it sounds.
So company owners would just rather decide to stick to one and try to polish it through the years and making themselves to be the best in service that no one can easily beat up.