Google didn't kill the Edge browser, Microsoft gave up. If Mozilla can have an independent from scratch browser, Microsoft of all companies could have one too. It's just easier and cheaper for them to rebrand Chromium and call it a day.
And I'm not buying the argument that progress on the Web (tech stack) should stop so that it's easier to make/maintain a browser.
I grew up in the dial-up era but personally think it's incredibly cool how I am able to use a full featured IDE, flash an ESP-32 or my phone via USB, make low latency Zoom/Teams calls with screen sharing, run language agnostic bytecode and utilize low level GPU access, all in a highly secure sandbox on my Macbook, Linux/Windows Thinkpad, $100 Chromebook, tablet and phone.
And I'm not buying the argument that progress on the Web (tech stack) should stop so that it's easier to make/maintain a browser.