They are not removing from the code base bro, they are slashing it off from the entire chromium core. If you're not too well versed with the subject, think of it as the rubber core of a tennis ball on which all chromium based browsers are essentially plastered on. Google made an amazing, cheap rubber core and all browser companies jumped on the game.
If Google starts to make the chromium core egg shaped, all resulting tennis balls WILL have to fit that shape. Opera, Edge will be completely unable to do anything about it. Brave might have a way to do it at a significant functionality and security loss because their chromium core is already somewhat adapted.
Only way forward would be to use some other core. Firefox runs on Mozilla Quantum core for example. They make their own rubber core round so they'll be able to make round tennis balls as usual. Safari has always been a step ahead with its webkit base (which is not an apple to apple comparison -pun intended, but it's not based on chromium, you can think that they directly make the tennis balls without a rubber core) so they'll have no problem either. Some less known webkit based browsers will function okay too.
This is what happens when projects are outwardly open source, but actually under the control of a profit based company. It's never a good fit. Chromium was always Google's brain child, and they can do whatever they want with it. We'll all have to tow the line or get off.
