Full-text search allows you to search for words in the content of statuses (if your instance has ElasticSearch configured), compared to the current version which only allows searching for hashtags.
In addition, you get a whole lot of search modifiers for advanced search (no UI for those yet):
has:image / has:video / has:audio / has:media
has:poll / has:link / has:embed
is:sensitive / is:reply
language:en
from:account
before:2023-08-08
after:2023-08-08
during:2023-08-08