Sui vs Solana vs lightning network as a payment network

What is the cost of sending 1 USD of a stable asset to my friend (ptop) on a network when 500M users are using it?

current Daily Active Users: ~250k (solscan or artemis)
current cost: 0.0000085 SOL * 20 USD/SOL = 0.00017 USD (solscan)
cost for 500M DAUs:

current DAU: ~ 100k (suivision or artemis)
current cost: 0.0025 SUI * 0.50 USD/SUI = 0.00124 USD (suiscan Avg gas fee)
cost for 500M DAUs:

Lightning network 1ml
current Daily Active Users: not available
current cost: 0.04 USD (Google Bard)
cost for 500M DAUs:

Note that the question asks “when 500M users”. It doesn’t really matter what a network can do when there are 100k active users.
Do we have simulated data to compare the networks for 500M DAUs?

At 500M DAUs, a ptop transfer of a coin (a single-writer object) will still be able to skip consensus. But what does this mean for the fee? Is the average gas fee of a transfer for a simple ptop transfer expected to stay more or less the same over time?



Feel free to chime in, suggest better resources or correct me where I’m wrong. I’ll update the post where required.