When will the burn rate of ethereum stop getting bigger?

I've been super excited to see we just hit a deflationary day and we or on the path to more burns!

I was preaching to my friend ethereum and where it's headed, and he asked me a question I couldn't figure out the answer to.

He asked if the eth rate is increasing and the goal is to get more eth burned than there is mined, will that go on forever or will it get to a point where they find a good burn rate and keep it at that? Or is it just like an indefinite thing?

Insight and links to resources is appreciated as I'd love to learn and share the info with my friend :)