I disagree. Theres nothing inherently small about the likes of Hibs and Hearts. There were 20,000 at Easter Road last night. That's twice as many as the 10,000 Millwall got last night. It's also more than Swansea got last night. It's more than Brentford get in the Premier League.
Even if they were in the lower reaches of the EFL, well when I was growing up in the 90s the very idea of Swansea, Cardiff, Brighton, Burnley or Brentford ever playing PL football would have seemed unlikely. But they all have. Theres no telling what the ceiling of those clubs would be if they had access to the same sponsorship and TV money of even the most mediocre clubs in England.