I'm for it in theory. I explored it for a while, since at least March 2010, cf https://fabien.benetou.fr/Tools/Bitcoin

But, sadly, I'm against it in practice. You can see that the same page hasn't been updated since 2016. This is because even though is does work, technically speaking (which is in itself a feat!), socially speaking the impact is IMHO negative. The main use case is speculation about itself and it comes at a huge side effect, namely energy usage (cf IEA's https://www.iea.org/data-and-statistics/charts/bitcoin-energy-use-estimates ). This isn't even about taking into consideration much worst usages, e.g money laundering. Another difference since the early days is that traditional institutions have started to use or sell them. This is very positive in terms of trust, namely that such institutions do a lot of checks because they are legally required too. This is though quite negative from my own ideological standpoint on the very raise d'etre of cryptocurrency because I was initially seeing it through the lens of anarchy, where participants in a system rely on each other and manage their own structure. Few interesting projects happened along those lines, both physically and digitally, but in practice those are, in terms of volume of transactions (and thus energy consumption) marginal. They are mere demonstrations.

So yes I was excited by the prospect, both socially and technologically, but since I've became disillusioned. Cool idea, even cool implementation, boring usage, literally life threatening effect to our one single planet. Not worth it.

I will add this retrospective to my Bitcoin page to reflect that soon.

PS: I understand that Bitcoin is not all cryptocurrencies. I also dabbled (and by that I mean code, including making my own transactions to explore smart contract before it was in the main blockchain) with other cryptocurrencies, including Ethereum. I also had few assets which I liquidated a little while ago from at least 4 different cryptocurrencies. I'm using Bitcoin as a simplification for others because that's where the value literally is today. I'd also argue, which is just me speculating here, that if Bitcoin falls, all other follows even if they'd be technically viable.