We steered into a corner that is hard to get out of...
Chrome has been becoming the new IE with the websites giving the best experience on Chrome - only. That's the risk.
What pipes the browser makers choose to rely on is between them and pipe makers I guess. Probably the pipe makers should focus on the developer experience.
they don't get to decide this if push comes to shove. Banks and governments in European jurisdictions obviously can be forced to comply with European laws and if there was some geopolitical question about security you can just force them to switch to a local fork of Chromium which given that it's open source is technically relatively trivial.
It's the same as Linux essentially. The overwhelming majority of commits comes from RedHat, Huawei and Samsung or other international corps which is fine because there's always the implicit option to fork it. We don't need fifty different kernels given that we're talking about open source software. In the olden days of Internet explorer and dependence on proprietary software this argument made sense because you could theoretically be squeezed without an ad-hoc alternative, but that's not the case any more.
From the long lasting first party cookies to the ease of fingerprinting the engine is designed to make advertising more effective. But hey who cares about privacy.