The increasing complexity of web browsers has less to do with companies using browsers to shoulder competition out (after all, why would they bother to make their engines open source?) and more to do with the web becoming the default application platform. And this has its roots in companies... trying to shouldering out competition with native UI frameworks. Microsoft just two days ago introduced WinUI, another propitiatory UI that's tied into their ecosystem. Bringing Microsoft's total non standard UI frameworks to seven (or is it eight?). Developers want cross compatibility, so they naturally turn to the web. Usually in the form of election or native web. And if they do choose to go native, iOS and Android on the top of the list now days.

So developers expect native OS level API access from browsers. This is the true source of the bloat. And to be honest, we're converging on an open standard cross platform API. this is great.