15 years ago, Firefox would cause my desktop computer to spin up its really loud fan once or twice an hour. It was a room away from my bedroom, but it was enough to wake up my (now) wife, who was angry, but unable to identify the source of the noise. That lasted for a few weeks before I noticed it during the day. When I switched to Chrome, it stopped.
It’s totally unreasonable, but it’s enough to keep me off Firefox. I’m sure both browsers have been rewritten multiple times since then.
Well, it was, until the whole “web integrity thing”.