Has been over-hyped for a long time but it might finally have a sound use-case IF swap services fail to recover, in some circumstances...

It allows for resizing a channel (down or up) at the same time you make another transaction.

This was hyped by LSP's because it allowed them to shrink the size of channels to inactive mobile wallets without having to close them and re-open, they could simply take their liquidity away and while the channel remains open. Arguably they would pass the savings on chain fees (lol) to users.

Another larp use-case was that you could increase the size of your channels from an external wallet, rather than depositing to your LN node and just opening another channel. This is kind of dumb since it is typically better to have more channels, and it involves some PSBT fuckery to coordinate with the external wallet, but again could save a bit on chain fees (lol)

With swaps potentially not being constrained, it may make sense now if you need to extract some on-chain coin to just shrink your channels and pay yourself out to chain.

To re-balance/refill a channel, I don't see the benefit, you could open a second channel and circular rebalance... swaps will always have been better for this particularly where swaps in were subsidized to encourage passive rebalancing of the swap providers channels.