I'm just looking at how it is currently used. If after all these years there isn't a positive use-case to offset it, there might not be one at all.
The biggest issue I have with cryptocurrency is that it’s an utter waste of resources. It incentivizes the consumption of electricity (and talent) purely to print money, rather than to produce value. Yes, currencies provide some value to society, but we already have more sustainable options.
I see the appeal if you hate taxes and regulations or live under a particularly oppressive regime. However, given that it relies, to some extent, on public infrastructure like internet and electricity that governments can outright shut off if they so desire, there are better options. Raw materials and bartering work pretty well. Just don’t invest in tulips.
Most of these countries barely have a stable internet connection or even stable electrical power, so I wouldn't surprised if these 'currencies' aren't so helpful in practice.
* Note that use by corrupt politicians to launder their ill-gotten gains is not a positive.
Yes, bitcoin can play a role but it's not like you're paying for your groceries in bitcoin. Cash under the mattress > blockchain
Perhaps these ransomware attacks are the market's way of making things... more fair.
Security improvements seem to be driven more by regulation (GDPR), competition (when did ElasticSearch release TLS support for free? Not after the Nth open ES cluster - only after Amazon competed with them), and large costs (switching to Linux servers because they're cheaper. Though there are concerns about current security practices there too...).