Asked Grok about lighting scaling:

### Theoretical Scalability
The Lightning Network (LN), a layer-2 protocol built on Bitcoin, is designed to address Bitcoin's base-layer limitation of ~7 transactions per second (TPS) by enabling off-chain payments through bidirectional channels. In theory, LN can scale to millions to billions of TPS across the network, far exceeding Visa's ~24,000 TPS average or ~65,000 TPS peak. This is achieved by routing payments via interconnected channels without broadcasting every transaction to the Bitcoin blockchain—only channel openings and closings settle on-chain. The original 2015 whitepaper by Joseph Poon and Thaddeus Dryja explicitly positions LN as a solution for \"scalable off-chain instant payments,\" capable of handling global volumes while preserving Bitcoin's security and decentralization.

### Practical Challenges and Limitations
Despite its promise, LN faces significant hurdles that prevent it from reliably servicing a full global economy today:

- Onboarding Bottlenecks: Each channel requires an on-chain Bitcoin transaction to open and close, consuming precious base-layer space. Bitcoin processes ~350,000 transactions per day (~4 TPS average). Onboarding 1 billion users (assuming 1-2 channels each) could take 32-64 years at current rates, even dedicating the entire chain to LN activity. Protocol upgrades like channel factories or splicing help, but they don't eliminate the dependency.

- Liquidity and Routing Issues: Payments require sufficient liquidity in channels along the route, and finding paths becomes inefficient as the network grows (e.g., high failure rates for transactions over $50, often ~60%). Users must be online for routing, or rely on watchtowers (introducing trust and privacy risks). Large payments can imbalance channels, requiring rebalancing that's costly and complex.

- Centralization Risks: Growth has led to hub-and-spoke structures, where a few large nodes (e.g., exchanges or custodians) dominate routing, potentially enabling censorship or single points of failure. Many users opt for custodial wallets (e.g., via apps like Wallet of Satoshi), undermining Bitcoin's self-sovereignty ethos.

- Current Network Metrics (as of September 2025): LN has ~16,000 nodes and ~75,000 channels, with total capacity at 4,200 BTC ($441 million USD). This is a 20% drop from 2024 peaks, attributed to efficiency gains (e.g., fewer but larger channels) rather than decline, but routed payment volume has surged 1,212% since 2021. Adoption is growing—e.g., 15% of Coinbase Bitcoin withdrawals use LN, and integrations like Tether's USDt on LN enable stablecoin remittances—but it's still niche, handling microtransactions rather than high-value global flows.

- Real-World Performance: Tests show LN struggling with >10,000 TPS in practice due to bandwidth, latency, and failure assumptions. Congestion on Bitcoin's base layer (from channel activity) could render it unusable during mass adoption spikes.

Critics, including developers like MartyParty and Rajat Soni, argue LN is \"cool but doesn't scale to Visa levels\" without Bitcoin hard forks (e.g., larger blocks), which are politically contentious. Alternatives like Ark or covenants (e.g., CTV+CSFS) are proposed to improve state management and reduce on-chain load.

### Global Economy Requirements
A \"global economy\" implies handling trillions in daily value across payments, remittances, trade, and finance for ~8 billion people. Key benchmarks:
- Volume: Visa alone processes ~500 million transactions/day (~5,800 TPS average). The full system (including SWIFT, ACH, etc.) exceeds 1 billion TPS during peaks.
- Value: Daily cross-border payments: ~$10-15 trillion; retail: hundreds of billions.
- Demands: Near-instant settlement (<1 second), 99.99% uptime, low fees (<$0.01), and resilience to failures.

LN's off-chain design meets speed and cost for small payments (e.g., remittances in El Salvador via Chivo wallet), but scaling to quadrillions in settled value would require:
- Massive node growth (millions of well-connected hubs).
- Internet infrastructure upgrades (current public internet can't sustain >50,000 TPS globally without congestion).
- Hybrid models (e.g., LN for retail + Bitcoin base for settlement).

| Aspect | Bitcoin Base Layer | Lightning Network (Theoretical) | Lightning (Current/Practical) | Global Economy Need (e.g., Visa-like) |
|--------|---------------------|---------------------------------|---------------------------------------|---------------------------------------|
| TPS | 4-7 | Millions to 1M+ | <10,000 (with issues) | 24,000+ average, 65,000+ peak |
| Settlement Time | 10-60 minutes | Milliseconds | Milliseconds (if routed) | <1 second |
| Fees | $1-100+ (variable) | <$0.01 | <$0.01 (but liquidity costs) | <$0.01 |
| Capacity | ~$1T market cap | Unlimited off-chain | ~$441M locked | Trillions in daily volume |
| User Onboarding | Instant (wallets) | Channel setup (days/years at scale) | Slow for non-custodial | Billions, frictionless |

### Can It Scale? Assessment
Potentially yes, but not imminently or standalone. LN has proven effective for niche use (e.g., 16% of CoinGate's Bitcoin payments in 2025, global remittances via Strike), and ongoing innovations (e.g., Taproot Assets for multi-asset support) could push it toward broader utility. However, without Bitcoin protocol changes (e.g., block size increases or better covenant opcodes), it can't onboard billions or handle peak global loads without custodial centralization—defeating Bitcoin's core value proposition.

In a multi-chain future, Bitcoin/LN could serve as a secure settlement layer (like \"digital gold\" for reserves), while faster chains (e.g., Solana at 65,000 TPS) handle retail velocity. True global scale might require ecosystem evolution, like @doublezero's efficient internet protocols. For now, LN scales Bitcoin for millions, not billions—making it a vital step, but not the endgame.