The support section of Mozilla's website warns that some users will experience a change to their default search engine in the March 98 release of Firefox 8. It is indicated that the change will affect users from all countries, but which search engines will be removed is not reported (the list is not defined in the code; search engine handlers are loaded in the form of add-ons depending on the country, language and other parameters). Access to the discussion of the upcoming change is currently open only to Mozilla employees.
The reason cited for forcing a change to the default search engine is the inability to continue supplying handlers for some search engines due to a lack of formal permission. It is noted that the search engines previously offered in Firefox were given the opportunity to sign a cooperation agreement and those systems that did not comply with the conditions will be removed. If desired, the user can return the search engine he is interested in, but he will need to install a separately distributed search plugin or add-on associated with it.
The change appears to be related to royalty agreements for referring search traffic, which generate the lion's share of Mozilla's revenue. For example, in 2020, the share of Mozilla's revenue from cooperation with search engines was 89%. The English-language build of Firefox offers Google by default, the Russian-language and Turkish versions offer Yandex, and the Chinese-language builds offer Baidu. Google's search traffic deal, which generates about $400 million a year, was extended in 2020 until August 2023.
In 2017, Mozilla already had the experience of terminating Yahoo as its default search engine due to a breach of contract, while retaining all payments due for the entire term of the agreement. From the fall of 2021 to the end of January 2022, there was an experiment in which 1% of Firefox users were switched to using the Microsoft Bing search engine by default. Perhaps this time around, one of the search partners has ceased to meet Mozilla's search quality and privacy requirements, and Bing is being considered as an option to replace it.
Source: opennet.ru