Nextcloud is the way.
Discussion
i mean
if you just want to be able to access a shared folder syncthing has a lot less overhead
syncthing is good for syncing local folders, but it's not a cloud provider. If you're looking to have a cloud-based repository that it synced or just made available to your local machines, Nextcloud is probably the best option. It really depends on the specific requirements so we can really only speak in general terms.
if its just "store photos and videos" then I wouldn't install an entire Nextcloud myself
Me neither. I was assuming he'd use it for general file storage as well. For just photos and video I would a provider that specializes in secure photo and video backup and gallery services. That's what I do. I use Ente Photos. It makes more sense for me to offload that functionality to a 3rd party provider than to build out my own own infrastructure.