it's currently sits at 130GB. It alone is responsible for more than 10% of all of s3 (+900 wikis) and en par with extlinks table of commons which has more than 100M pages.
A quick search showed this:
mysql:research@dbstore1007.eqiad.wmnet [ruwikinews]> select el_to_domain_index, count(*) from externallinks group by el_to_domain_index order by count(*) desc limit 5; +----------------------------------+----------+ | el_to_domain_index | count(*) | +----------------------------------+----------+ | https://org.wikimedia. | 27202031 | | https://org.archive.web. | 6866861 | | https://org.toolforge.pageviews. | 6800521 | | https://org.wmflabs.tools. | 5793662 | | https://com.twitter. | 1603551 | +----------------------------------+----------+ 5 rows in set (9 min 5.839 sec)
27M links are just to the rest API. This shouldn't be considered external domain:
| 332698561 | 13972941 | https://org.wikimedia. | /api/rest_v1/metrics/pageviews/per-article/ru.wikinews/all-access/user/%D0%92%D0%B5%D1%81%D0%B5%D0%BD%D0%BD%D1%8F%D1%8F%20%D0%B2%D1%8B%D1%81%D1%82%D0%B0%D0%B2%D0%BA%D0%B0%20%C2%AB%D0%9A%D0%BB%D0%B8%D0%BD%D0%BE%D0%BA-2023%C2%BB/daily/2015070100/2023040315
And https://org.wmflabs.tools. and https://org.toolforge.pageviews. and https://org.creativecommons. should switch to interwiki links