Check out /r/Bitcoin sometime for users complaining about transactions fees :) (Actually more the threat that some day there will be significant fees)

Unfortunately Bitcoin has often been oversold as being "free"; but if transactions are free, and there's a fixed number of coins to mine, who pays for this whole network in 30 years?

The motivation behind the design of LN is to minimize the number of transactions which need to be globally verified (which has a cost) while still adhering to the general model of Bitcoin (decentralized, pseudonymous, etc).

You're right though that with tx fees being on the order of ~0.05 USD, you don't really need LN yet. I've long assumed that fees would become significant, pushing out some use cases. That's already happened with e.g satoshidice.

Uh oh ... for all I know, r/bitcoin is not a free community but gets heavily censored. A more balanced perspective can be found on r/btc:

https://www.reddit.com/r/btc

So you say LN is to solve future problems. Because transactions are free and in 30 years nobody will do the mining for free. Well, thats why bitcoin has fees. And a mechanism to let the market decide on those fees. This has been planned from the beginning.

From what I can see, all is fine with bitcoin. And there is no need for the complexity LN brings.

It's already infeasible to directly make a single spend of $0.0001 on the blockchain itself (transaction fees are $0.02-$0.05).

What is the use case of spending $0.0001?

Downloading a webpage, for example. Sending an email, giving someone an upvote, making use of a caching service.

Basically any sort of payment you would want to do at the machine level. If I'm uploading a file to you, I would want you to pay per MB because I'm not sure if you're going to leave after you have 50% of the file.

> who pays for this whole network in 30 years?

Why pays to seed torrents? Who pays to run NTP servers? Who pays for running game servers? Its is wrong to assume that something has to be profitable in order for it to exist.

Running the Bitcoin mining network costs millions of dollars per day in electricity costs alone. Who's going to to pay that when the subsidy goes away?

You are wrong about mining costs. Miners are estimated to consume 100-200 megawatt. Most of them pay below worldwide average electricity prices, being located in Iceland (KnC), WA state (BitFury), etc; maybe around $0.05/kWh. So the miners' daily costs would be $120 000 to $240 000.

The block reward only halves, it doesn't "go away". Unless you are talking about when it can't halve anymore because of the 8 decimals limit, which we could just remove, just like Satoshi wanted (same situation as with block size limit).

If we keep the 21M limit, subsidy will be insignificat at one point.

If both transaction fees and the coinbase are zero or negligible, there is potential revenue in mining: to reverse transactions and rip people off.

Altruism certainly exists, but assuming that altruistic actors (rather than self-interested actors) will expend more resources than attackers is a very different security model than what Bitcoin is designed upon.

For the past month there has been a backlog of 6000 to 10,000 transactions in the mempool.

This is causing nodes to go offline. There are about 500 to 1000 rasberry pies operating as full nodes on the network and their 1 GB of ram is not enough to hold the backlog of tx.

Blockstream is proposing to raise the limit to 2MB 2 years from now. That would be a disaster for the network.