You can even verify that all channels have funds locked onchain:

Gossip Protocol Messages

... channel_announcement: A blockchain anchored proof of the existence of a channel between two individual nodes. Any third party can verify this proof to ensure that a real channel is actually being advertised. Similar to the node_announcement, this message also contains information describing the capabilities of the channel, which is useful when attempting to route a payment. ... It's important to note that each component of the channel graph is authenticated, allowing a third party to ensure that the owner of the channel/update/node is actually the one sending out an update.
-- Mastering the Lightning Network, Chapter 11: Gossip and the Channel Graph (p.276-277)