What's the ultimate goal of these companies? Of any company?
I find that it's very difficult to know, truly, what these mega corporations want. What does apple want? For everyone to use apple? Probably not, if this was the case they would be releasing much cheaper products.
So I think companies have a market segment they want to dominate, and of course there are some areas of conflict. Say, twitch is owned by Amazon and Google with YouTube also feels part of that space is owned to them. In this sense, they are no different to another form of social organisation we are fairly acquainted with: empires.
Now, why couldn't everyone just form their own society back in the day and live chill and not submit themselves to the rule of the empire? Well, the answer to that is that if the empire felt you belonged to them then they would simply swallow you.
So, to answer your question, people are building their own businesses but as soon as these become threatening in any way to the empires that rule these lands then these businesses are squashed. But that's exactly what is supposed to happen, if you can't take on the pressure then such is life.
I guess the sad news is that, even today, we still have empires ruling over us. But I would argue that quality of life, inequality, social liberties have all gotten better with every passing empire. What does the future of business look like? I'm not sure.