A much smaller Dyson sphere, halfway to Mercury, would be 23 million km across. If we made it just 1 centimetre thick, we'd need 66 billion billion cubic metres of material. If we made it out of steel, at current rates we'd take 280 billion years to produce enough.
If we could mine and use literally all the physical substance of the planet Mercury, that wouldn't be enough.
‘A Dyson sphere *around* the solar system. Guys, I don’t know if it’s possible™️ but anyway, this is my pitch. Please invest billions in me.’ VCs: ‘We must shower this disruptive thinker in cash.’
But if you preface nonsense with “maybe” it’s science.