Like this recent post on Chemistry SE which is the collection for different types of resources for learning Chemistry ( which I find quite useful) do we have any such thing over here at Physics SE? If not, then why not? Is it possible do it( if it isn't already available)? What I think is that if we too start such a project then it would help in gathering all those scattered resource recommendation at the same place and help the learning community.
Phys.SE has a central/primary Book recommendations, although it is currently closed and locked. The reason for the latter is partly because maintenance takes a lot of time.
Currently Phys.SE has also more than 1500 secondary res. recom. qs.
Online resources are viewed as part of res. recommendations, cf. its tag wiki. However, Phys.SE usually does not accept res. recom. qs that specifically ask for online resources only, partly because they are prone to link rot. On the other hand, Phys.SE allows answers that only recommend online resources.