I'm saying that "You don't need to hit a huge number of service providers because the USA market is highly concentrated" is not a good argument because the act of taxing the concentrated incumbents will cause changes.
Also note that the micro-service providers might just be white-label resellers of the big providers.
Which supports my general point that services are hard to tax because unlike physical goods you can't force them to flow through a few physical choke-points. The fact that economies of scale and other factors cause them to naturally collect in a few concentrated firms in the absence of taxes does not mean that you can just tax those concentrated firms because they will figure out ways to not get taxed!
Also note that the micro-service providers might just be white-label resellers of the big providers.
Which supports my general point that services are hard to tax because unlike physical goods you can't force them to flow through a few physical choke-points. The fact that economies of scale and other factors cause them to naturally collect in a few concentrated firms in the absence of taxes does not mean that you can just tax those concentrated firms because they will figure out ways to not get taxed!