History is on your side on this one, to a large degree.
How many of the innovations that we enjoy the descendants of today were created by researchers at Bell Labs? The BBC? Both of those were essentially monopolies. They had the money and motivation to invest resources on fundamental research that occasionally yielded technology that we all use today.
One difference now is that all the behemoths you allude to are publicly traded companies. Wall Street usually does not reward a company spending money on something that doesn't yield large short term possibilities. Basic research doesn't fit into that category. A company like Alphabet may be publicly traded, but much of the voting power for the stockholders sits in the hands of a couple. So, they can call the shots. That's kind of unusual.
Along those same lines, most people are not interested in the long haul and aren't willing to do what the likes of Hewlett and Packard did. Besides, have you looked at rent for a garage these days?
Really interesting topic and thoughts - thanks very much!