Computers have existed for nearly 70 years. Bitcoin has existed for what... 13 years?

While the GBP value has changed over the course of 600 years, (of course it would, peoples and governments change in that same timeframe) hasn't a BTC as well?

If I sell an item worth $60,000 USD for 1 BTC, the next day the 1 BTC could be worth $40 or $50,0000 USD. Surely such volatility cannot be useful for a common currency.

"Stable coins exist" - and yes, they do - but if a stable coin is pegged to a currency, why do you not just use said currency?

I don't know what a reasonable expectation is for the longevity of a currency; I mean, in dog-years, I'm dead.