My example I have in mind, is a charity in the developing world in a really broken, poor country.

The locals don't have the sats to open a lightning channel, and they can't trust the 'custodians' to give them their funds in the region where they live.

And they can't afford the on-chain fees, main-chain, just to accept enough UTXOs to open a lightning channel so they are left with 2 choices.

Either not use Bitcoin because it's not affordable... (provided they can run BTCPay server at all) or...

Run BTCPay server on a website, accept donations via lightning QR code (BTCPay) and have those donations automatically converted to Liquid (Lightning->Liquid).

Once enough Liquid UXTOs build up to a few hundred thousand sats... they're used to open a lightning channel. The liquidity is then managed automatically for them as "receivers" using Liquid

With the ultimate goal of stacking enough sats to create long-term, savings-oriented, fee-efficient Bitcoin UTXOs that they can use for important reasons.

That is the purpose of Liquid - it's not 'to use Liquid' it's just a temporary medium in struggling parts of the world.