It's because startups rarely have time and resources to create a solid infrastructure from the beginning. Easy and simple are preferred. The product needs to be

It's because startups rarely have time and resources to create a solid infrastructure from the beginning. Easy and simple are preferred. The product needs to be launched and validated as fast as possible. So by the time a product becomes successful, it's core is already using inefficient solutions. And very few companies upgrade them because the effort is not really worth it business-wise. If we would have been driven by real solutions instead of money, then P2P would probably be king. Direct communication everywhere.