SegWit opens the opportunity to introduce sidechains. These are less secure than on block scaling, but their hope is that they will be good enough.
Ignoring all the economic consequences, what we have in segregated witness is the illusion of scaling.
What they have in fact introduced as a 2 MB block and segregated witness at the same time. Increasing the block size is a scaling solution. Segregated witness is not. Segregated witness with a standard weight provides between 1.2 and 1.6 times the transactional throughput based on a 1 MB partial block and a 4 MB full block.
The reality of this is we have 4 MB masquerading as one. In a secret 2x option this is doubled.
Contrary to what you are been told, the witness information, that is the digital signatures are important. These have probative value. This comes down to this idea that code is law once again and that they can just simply bypass everything in a typical anarchist BS format. It does not matter what users do, it matters what exchanges and businesses do. These entities can be forced to comply and they will be. In some places, such as Victoria in Australia it is actually a criminal offence to delete data that is associated with financial transactions. For general users, pruning this information is not an issue. It is an issue for merchants and other companies. Under the legislative provisions they will be required to maintain the full data.
Consequently, it is an issue of a scaling solution that is not providing scale. It is the blocks I increase and not segregated witness that provides any increase. What we have is a typical magician's trick. It is a bait and switch. You look at the introduced information as they have you look away. What we really have is a 150% increase at a 400% cost. The simplicity of this is just increasing the block size provides 260% more throughput without SegWit.
Putting it another way, segregated witness has 62.5% overhead. That is it reduces throughput by two thirds.
In many ways, this is the biggest confidence trick to have ever occurred within bitcoin. It makes Mt Gox seem mild.
I say this again so that people understand it.
Segregated witness increases the amount of data storage and network traffic by 400% to gain a transactional throughput of 150%. Simply introducing a 4 MB block or in SegWit 2x and 8 MB block will gain 400% and 800% of the throughput respectively.