It blocks lots of ads by default, some sites don’t like that. Also, if you default to https: or are using TOR features, that will slow things down.
Straight Chromium should be efficient.
I have a puzzlement on my Windows 10 desktop. I use three programs to search/read the web; DuckDuckGo with Opera, Microsoft Bing, and Brave. When done on the web, I close all browsers and run CCleaner. It tells me that Edge Chromium is running and asks to close it. I click okay, it says it’s taking a long time and should it force it. A couple of seconds after I say okay, CCleaner starts. When I look on Task Manager when I get the first message, Edge doesn’t show as a running apt.