I should clarify that by "most use cases" I'm not envisioning a bunch of cryptogeeks [us, or at least myself and a few of us] happily buying up hard disks, waiting hours, days, weeks to spawn up new full nodes. I'm envisioning a world where every person has access to this technology and finds it practical, convenient, and safe ti use.
- Eric Lombrozo
Blockchain validation has become too expensive to properly secure the network as per our original security model. The level of validation required to comply with our security model has become completely impractical for most use cases. Block space is still cheap only because of block reward subsidy (which decreases exponentially with time). The economics are already completely jacked - larger blocks will only worsen this disparity.
The only practical way for the network to function at present (and what has essentially ended up happening, if often tacitly) is by introducing trust, in validators, miners, relayers, explorer websites, online wallets, etc...which in and of itself wouldn't be the end of the world were it not for the fact that the raison d'etre of bitcoin is trustlessness - and the security model is very much based on this idea. Because of this, there's been a tendency to deny that bitcoin cannot presently scale without trust. This is horrible because our entire security model has gone out the window...and has been replaced with something that isn't specified at all!
We don't really know the boundaries of our model, as the fork a couple of days ago demonstrated. Right now we're basically trusting a few devs and some mining pool operators that until now have been willing to cooperate for the benefit of the network. It is dangerous to assume this will continue perpetually. Even assuming the best intentions, an incident might occur that this cooperation cannot easily repair.
We need to either solve the validation cost/bottleneck issue...or we need to construct a new security model that takes these trust assumptions into account.
- Eric Lombrozo