Scalability is a big bottleneck because the Ethereum blockchain is almost full. If you're a bigger organization, the calculus is that if we join, it will not only be more full but we will be competing with everyone for transaction space.
Analysis
In 2018, Ethereum faced congestion due to high demand (e.g., CryptoKitties), but the blockchain was not 'full' in a binary sense. Gas limits and dynamic fee markets meant transactions could still be processed, albeit at higher costs. The 'competing for transaction space' part was accurate, as block space was a scarce resource.
Background
Ethereum's scalability issues were widely acknowledged in 2018, with solutions like layer-2 (e.g., Plasma, which OmiseGO used) and later Ethereum 2.0 (now Consensus Layer) in development. Buterin often highlighted these constraints to justify scaling research.
Verdict summary
The statement oversimplifies Ethereum's scalability challenges in 2018, as 'full' is a relative term and not a strict technical limit.
Sources consulted
— Ethereum Improvement Proposals (EIPs) on gas limits (2018)
— Vitalik Buterin's 2018 blog posts on scalability (e.g., 'Ethereum’s Scalability Roadmap')
— OmiseGO AMA transcripts (2018)