I had to laugh a little while reading this, searching for nextcloud and syncthing integration. I’m not 100% sure how right Jos Poortvliet is about scalability. Sure syncthing consumes more RAM/CPU because the design is different (block indexes) compared to a “simple” webdav share.
The statement “it seems a non-enterprise, home user tech” with the sentence before “it is not an PHP app” smells like Eating your own dog food. Enterprise solutions are always a mix of a bunch of software packages.
The scalability answer isn’t very convincing - sure, syncthing works with 2000 devices. Enough for, say, 1000 users. That is a medium size customer of ours - bigger ones have 100.000 users, say 150.000 devices. Some customers have millions of users.
Then about using the syncthing protocol in our client instead of webDAV.
We picked webDAV because it is a standard that is widely supported and works through any firewall. Syncthing uses its own, special protocol - which you can’t just mount in mac or windows, nor use from third party apps, and if it doesn’t use port 443 it won’t work through many firewalls.
Also, syncthing isn’t a PHP app so it can’t be installed easily on Nextcloud or integrated, especially in a large scale environment.
Sorry, it seems a nice non-enterprise, home user tech. Not really suitable for Nextcloud which has to work in a serious setup.
Look, if it is delta-sync and lan-sync you want, those are perfectly possible in Nextcloud. Just not done. Find a C++ developer and bug him/her to contribute these features to Nextcloud. Heck, deltasync is already mostly done and its developer wants to put it in Nextcloud - LANSync can be done, too.