> Is it practical to use Bitcoin for day to day life for one to two thirds of people if the transaction fee is now $24?

Yes, but the transaction fee is typically about US$15 these days, down to US$5 or so if it's the kind of thing you can wait 24 hours for. This is about the same cost as Western Union. Today there's a lot of trade volume as people panic, but the latest block https://blockchain.coinmarketcap.com/block/bitcoin/671850 contains fees ranging from .023 mBTC, with a bunch of transactions paying .042 mBTC up to 58.7 mBTC. The block reward including fees was 7763 mBTC, of which 6250 mBTC is the mining bounty and the other 1513 mBTC is transaction fees for the 2900 transactions in that block, a mean of 0.52 mBTC. The median transaction in that block paid .341 mBTC:

https://btc.com/00000000000000000000476ab57eea9be8ada36e2680...

The recommended fees from earn.com (previously blockchain.info) are currently 102 satoshis per byte for immediate inclusion and 88 satoshis per byte for inclusion within the hour, but this .341 mBTC median from the last block is generally 140 satoshis per byte.

https://bitcoinfees.earn.com/api/v1/fees/recommended

In dollars at US$50/mBTC, this means that the latest block included transactions that paid as little as US$1.15 and as much as US$2935 (!!!), and a whole bunch of transactions that paid US$2.10, but the mean is US$26 and the median is US$17. That means about 1400 of those 2900 transactions paid less than US$17.

But yeah, this is not what you want to use to pay for a can of Red Bull or even a restaurant dinner. It's more like Western Union or US$100 bills or gold. For example the current underground market spread for dollars is AR$142 buy, AR$147 sell, which is a price you will not get for small bills like US$20:

https://preciodolarblue.com.ar/

In effect every time you buy US$100 for savings from one of the "blue market" currency dealers (travel agencies and the like) you are paying half that spread, AR$250 or US$1.70, to the money changer. 1.7%. The break-even point where this is more expensive than the Bitcoin transaction fee is US$16000 for a US$26 fee, US$10000 for a US$17 fee, US$1200 for a US$2.10 fee, or US$700 for a US$1.70 fee. And, as you point out, lots of Bitcoin transactions happen inside of a single vendor platform like Coinbase and so don't pay the fee at all.

Usually cashing out your savings so you can buy a car or pay the rent or buy food or whatever is an every-month or every-few-months kind of thing. But you're still buying food on a day-to-day basis.

Even if you're using Bitcoin in an ATM-like fashion, paying a fee of US$15 or so every time you withdraw US$200, it's in the "everyday financial bad decisions" category, not the "totally impractical" category. (I hear ATM fees are a lot lower than that in the US now. Sadly, not in Argentina.)

Early on I avoided Bitcoin because I worried it might destroy civilization—after all, I rely on public streets, the public education of the people around me, and the public hospitals, not to mention the police, all funded by tax dollars. And there's been a cogent argument since Tim May presented his manifesto at Hackers (01991? Certainly before early 01993, when I read it) that cryptocurrencies would inevitably kneecap taxation and thus cause the collapse of governments.

But the US election in 02016 made it clear that civilization is doing a perfectly fine job of destroying itself before losing any significant taxability to Bitcoin or other cryptocurrencies, and the best we can hope for is to salvage its crown jewels from the rubble.