High CPU usage in Chrome/Opera When I open 1-2 tabs with sites that have many images (e-shop as an example) the CPU usage gets to 100% for Chrome/Opera/Firefox.
What I've tried:

Reset Chrome to default settings
Disabled all extensions
Disabled &quot;Use hardware acceleration&quot; in Chrome settings
Checked task manager in Chrome. Couldn't find anything except that a process called &quot;Browser&quot; takes all the CPU (100%+)
Run malware check on MacOS with 2 different programs (avast and malwarebyte)
Run diagnostics after restarting MacOS

Looks like any browser with webkit engine suddenly started consuming 100% CPU on any site which has at least some dynamic content, maybe images or some JS or something like that. Basically any site.
MacOS version: Big Sur 11.1
CPU: 2,5 GHz Quad-Core Intel Core i7
RAM: 16 GB
Graphics: Intel Iris Pro 1536 MB
Having the same issue. It's not very good even in Safari. I suspect the mtlcompilerservice, as I load pages I see a lot of instances of it in the Activity Monitor, consuming high CPU. TGPro shows high temperature of the CPU, 90+ celcius. Video playback heats up the device but loading pages and browsing around is the worst offender.
I have the 15&quot; mid 2014 model with Iris Pro &amp; Nvidia gt 750m. I thought the reason for overheating/fans-kicking-in-whenever-they-please was that Apple changed some things as to how GPUs work in Big Sur.
I'll try installing Big Sur to a separate volume, and if that doesn't help, I'll re-install macOS, starting from High Sierra and update here.
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Idle temp: 54-60 C  Browsing: 70+ C