I harvested the CTAN DB to research this. The results:
1390 github.com
90 gitlab.com
36 sourceforge.net
31 codeberg.org
20 tug.org
18 framagit.org
16 bitbucket.org
10 git.gnu.org.ua
8 gitlab.gutenberg-asso.fr
8 gitee.com
6 dickimaw-books.com
5 puszcza.gnu.org.ua
5 heptapod.host
3 git.robertalessi.net
3 git.framasoft.org
2 lists.tug.org
2 git.sr.ht
2 gitlab.ti.bfh.ch
2 gitlab.inria.fr
2 gitlab.adullact.net
2 gitea.com
1 uds-datalab.github.io
1 tufte-latex.github.io
1 todo.sr.ht
1 texnia.com
1 svn.tuxfamily.org
1 svn.gnu.org.ua
1 svn.code.sf.net
1 svenharder.github.io
1 savannah.nongnu.org
1 savannah.gnu.org
1 repo.or.cz
1 qa.parsilatex.com
1 plmlab.math.cnrs.fr
1 osda.ws
1 latex-project.org
1 humenda.github.io
1 guitex.org
1 git.umaneti.net
1 git.savannah.nongnu.org
1 git.savannah.gnu.org
1 git.ortolo.eu
1 git.linta.de
1 gitlab.science.ru.nl
1 gitlab.reutlingen-university.de
1 gitlab.git.nrw
1 gitlab.fi.muni.cz
1 forge.apps.education.fr
1 bastien-dumont.onmypc.net
1 archiv.dante.de
The 3 most common forges for LaTeX projects are shitty centralised walled-gardens (MS Github, Gitlab, & Sourceforge). Only 174 projects out of 1690 are using open access free-world/decentralised forges (~10%).
It is disturbing indeed. It also means reporting bugs on ~90% of LaTeX pkgs requires dancing with an evil gatekeeper, licking boots, etc.