You can build slim frontends that barely put load on the server. Or you can build fullblown monsters that put "a bit more" load on the server (and the browser). So, it's not only not-UX.
Bitcoin will be doing something for a few years. Possibly high volatility which continuously decreases. But with a few peaks of excitement (positive and negative) when breakthroughs or breakdowns are announced.
Then, at some point it will start. At first only small transactions that nobody really notices. Very small hints. People ensuring that their wallet cannot have been hacked. Nobody believes them. Nobody really realizes that large cashouts are commenced.
Then rumours spread that indeed strange transfers exist. Transactions nobody can explain. Even the 7500 coins, believed to be lost on a UK waste dump, are now moving again. The cashouts increase. Rumours about a critical flaw in the concept of bitcoin circulate.
It will take some time. Then the realization sets in. Somebody out there has a quantum computer equipped with enough qbits to break ecdsa-256...
This is totally in accordance with: "Work expands so as to fill the time avaible for its completion." - which I found to be very true. I'm so much more productive, when time restricted. And even more so when schedule restricted, because you can't just say you take a short break which then extends for hours.
