Businesses want to reduce risk, reduce overhead and maximize profits. Lenders want to reduce risk and maximize return. Customers want their assets protected and want fraudulent charges to be reversible. Other businesses in other countries want to know what to expect when dealing with businesses in yours. Having a known regulatory framework and a system of laws regarding commerce, trade and consumer protection facilitates the level of efficiency and complexity necessary to have the economies of scale we currently do.
Almost everything else you list is a matter of scale. As far as industrialization goes, all that industry requires an infrastructure, which itself requires an infrastructure, adjacency to materials, shipping, energy and a labor pool which won't be paid well enough to simply drive in to work from wherever. Even mere agriculture can be considered a centralization of hunting and gathering - as you needed one place to keep all the farms and the slaves and the temples and preferably all of that close to a river. It's not irrational. In fact, I believe the more difficult argument is in favor of decentralization - Bitcoin is attractive to speculators, scammers and hipsters but why would it be attractive to businesses or the average consumer without a proxy for the existing legal apparatus?
Gmail is not "the single location to email", it's simply the leader, there are still many email services out there, you can host your own email server if you want, it's (probably) not illegal. Is Google not an example of a free market working as intended? Surely, just because a free market suggests there should be competition, it doesn't imply there must be. You don't have to use Facebook if you don't want to. Sure, everyone you know is probably on facebook but you're free to try to create your own social media site and compete, or simply not use it. The market decided on facebook, if you don't like it, well, too bad I guess. Github exists because someone decided an online version of git would be successful, and they were right, it is. The market chooses winners, either honestly or dishonestly, legally or extralegally, and eventually the winners dominate, which Facebook and Google do.