Firefox

I can't remember the last time I ever got that message before I installed the DDG extension a couple years ago. I think the extension overrides it, so I can't say for the past two years on my actual personal browser. However the only times I remember it offering to change it since I started using it in 03~04 has been when they really tried making sure people knew that the default could be changed (which might have been in some way tied to stuff like the EU making even OSes show options for browsers to install when first setting up). And the others were when they first changed to Yahoo and after the contract with Yahoo ended.

That all being said, I think it is good to maybe once a year to have like the first update of the year or first major update ask. As never being shown other options just keeps smaller or newer competition from even being seen. DDG is a bit of a weird one since I both heard of it from being a "tech" person and because they went hard in advertising. But when I found out about the "Bangs", it was fucking over. Being able to change search engines from the one I am using was game changing to me. And seeing that it is becoming a thing for other ones is very nice to see (Brave being the main one I also use).

That all being said. I think there has to be some bug if it is making you fix your settings that often.