2. There are already alternatives which have better censorship resistance than Bitcoin, limiting the block size does little to fix those issues. I also don't think the market actually values censorship resistance in their digital cash as much as you think.
Alphabay processed $600,000 to $800,000 per day [1]. This is economic activity for tangible goods. In the list of other top uses of the blockchain might be ICOs, which are a way to leverage censorship resistance to raise money without permission from the SEC. On the high end, these accumulated hundreds of millions of dollars within minutes.
Please show me a use case for a blockchain-based cryptocurrency that even comes close to these numbers and that does not need censorship resistance.
[1] https://www.wired.com/story/alphabay-takedown-dark-web-chaos...
The estimate of daily volume provided by blockchain.info obscures our discussion, especially if you consider that the daily volume for BTC/USD pair is around $1B. There could be $1B-worth of outputs in a day all dedicated to providing liquidity to exchanges, but entering/exiting the network is not an application of the network itself.
As for anonymity and fungibility: I believe tumbling services are good enough today, which is why buying on a dark market works. However, it is not perfect and this is why projects like Monero, ZCash, MimbleWimble, TumbleBit and Xim are important.
This isn't the most accurate thing, but looks to me like several millions USD worth of volume just in Bitpay. That doesn't account for all of the other payment processors, or the peer to peer payments, or the exchange trading, etc. I'm not saying dark markets aren't an early driver of Bitcoin, but it's not where the majority of the action is now at all.
Exchange trading is not really using bitcoin, it is buying/selling bitcoin. This is like saying buying a car is an application of cars...
Having said that, Bitpay is processing more than I thought. The data in that article would mean it's about $5M per day... I'd love to see a breakdown of this to figure out why people are spending bitcoin for everyday things if it'd be better for them to just use a credit card (to get rewards, to not have to hold a volatile currency, for consumer protection, for faster payments, etc.)
That and you can buy cash-like goods like gold bars which would be prohibitively expensive or impossible to purchase via credit card.
Bitcoin is almost 10 years old. We have enough data now to be able to build strong cases for what it's actually useful for. It is no longer sufficient to talk about what Bitcoin will do without talking about why it has not done so yet.
2. There is no non-blockchain alternative to online censorship resistant cash. So if the price to use it is high, you will either pay the fee for censorship resistance or use your credit card (which is faster, cheaper, gives you rewards or cash back, provides consumer protection, etc., but is not censorship resistant). Altcoins basically act as market forces which allow us to discover what the world is willing to pay for censorship resistant digital cash, and you see this when markets which actually need censorship resistance (eg. Silk Road, AlphaBay, etc.) talk about considering Monero or something else when Bitcoin's fees get too high.