Read about how brave search index functions in detail. https://support.brave.com/hc/en-us/articles/4409406835469
Read about what is goggles feature that they are launching in detail https://brave.com/static-assets/files/goggles.pdf.
Brave search has recently come out of beta and is quite a new product.
Your opinion that yandex censors less compared to western search engines is wrong (IMO). Yandex bows and obeys what russin federation asks them. Meaning just as some western search engines will bury pro-russian content, yandex will bury pro-western content.https://reclaimthenet.org/yandex-adds-misinformation-labels-as-russia-warns-media/ (the yandex thing currently is not similar to ddg/qwant but will eventually increase.)
I have no idea who the author of the substack article is, but I don’t think he is well versed in tech topics. Yandex is a good search engine, no doubt about it, it is best for searching torrents/porn/pirated stuff/reverse image search.
Afaik, the author of the article does not seem to know much about mojeek or how it functions. Do read about mojeek a bit further.