Calibre has a total of 20,305 entries to translate - considering all resources, including manual, server, main calibre and site.
Now look into the top 20 translated languages (picked as the languages that get most attention from translators) to see if they also get attention for the site translation.
If you see the website file stats you will see low numbers.
Low numbers will get lower in the future (more entries added in each release) and will get less attention from translators as the task gets bigger (when lots of entries are not relevant)
To motivate users to translate the website the total number of entries to translate (1,284 entries) should be lower as this is a work made for new users to profit, not actual power users (that focus into the Calibre interface and server... and some manual pages)
Site file translation of 1,284 entries
https://www.transifex.com/calibre/calibre/website/
Languages not included in the Calibre site:
Portuguese = 31.78%
Czech = 17.29%
Dutch = 16.82%
Polish = 10.51%
German = 9.5%
Italian = 4.98%
Norwegian Bokmål = 3,58%
Chinese (China) = 1,56%
Malay = 1.25%
Turkish = 2.96%
Catalan = 1.79%
Icelandic = 0.78%
Galician = 0.78%
Almost very low number. And note those are in the top 20 most translated language for Calibre, all of them with more than 40% translated of the full 1,284 entries (21985 words).
It will be difficult to see some of those languages to be used in the Site!
And just to present all the numbers... languages used in the Calibre site:
Portuguese (Brazil) = 100%
Ukrainian = 100%
Spanish = 99.38%
French = 97.51%
Estonian = 51.48%
Swedish = 45.02%
Russian = 41.51
Chinese (Taiwan) = 21.5%