Proper antitrust reform would have broken up tech giants like Amazon, Google, and Apple by now.

I'm no antitrust expert but it seems to me that the "ecosystem" form of anticompetitive behavior completely evades regulator scrutiny.

For example, Amazon isn't the market leader in groceries, but they very clearly use their massive conglomerate advantage to outperform rivals where they've been making inroads. Kroger can't get the technology to eliminate cashiers, they can't get as much personal information about their customers compared to Amazon knowing the shopping habits of basically everyone via Amazon.com, they can't get the delivery logistics to compete on grocery delivery, and they can't buy computing at wholesale prices to run their information systems (and they can't use the most popular cloud computing provider because they're a direct competitor in, strangely, groceries).