I was disheartened to see this in the Sitecore docs:
Important
Search result boosting works in Solr version 6.6 or earlier, but Solr changed the implementation in Solr 7, and later versions. Therefore, search result boosting is broken in Sitecore 9.1, 9.2, and 9.3.
In SItecore 10, and later, item-level boosting works again, but field-level boosting does not. Sitecore stores the item boosting factor in a separate field in the Solr index ((__boost : pfloat). Sitecore uses the value in this field for boosting.
Has anyone figured out a workaround for this?
Specificaly, I have a index with items from two data sources - so the datasource field in the index is "sitecore" for my sitecore items and the other is "customdatasource". I was trying to boost when this field equaled Sitecore, so the sitecore results returned first.