I tried a couple of weeks ago. my conclusions were solidly in favour of google, despite reluctance on privacy concerns
I felt that for technical searches past a certain number of keywords (2 or 3), ddg and brave tend to lose focus where google doesn’t, a problem exacerbated by the lack of quote search on either
google also much better answers local questions, like “[supermarket] [location] opening times”, and indexes wikipedia more usefully, plus ten other integrated features you don’t miss until they’re gone (e.g. imdb)
I didn’t notice a change in SEO spam between the alternatives. I would imagine brave have made an effort here, but as far as I know, duckduckgo filters their content less than google does
finally, brave lacks maps, which is incredibly annoying