Yes, this is correct. Google pays Mozilla hundreds of millions of dollars annually to be the default search engine. This makes up the vast majority of Mozilla Corporation's revenue. It's somewhere in the ballpark of 85% of all their annual revenue last I heard.
They've tried hard in recent years to get out from under Google by diversifying into other areas. For example, they have a VPN service that is a wrapper around Mullvad, and they've made some privacy tools that you can pay to use, also largely wrappers around other companies' tools.
I was an employee of Mozilla Corporation and saw first-hand the effort they were making. In my opinion, it's been a pretty abysmal failure so far. Pulling Google funding would effectively hamstring Mozilla Corp.
They've tried hard in recent years to get out from under Google by diversifying into other areas. For example, they have a VPN service that is a wrapper around Mullvad, and they've made some privacy tools that you can pay to use, also largely wrappers around other companies' tools.
I was an employee of Mozilla Corporation and saw first-hand the effort they were making. In my opinion, it's been a pretty abysmal failure so far. Pulling Google funding would effectively hamstring Mozilla Corp.