calling a 300MB block ‘big’ is delusional

“Gotta pump up those numbers, those are rookie numbers!”

I agree, on the grand scheme of things, this is still small.

Their affairs only hurdle was BSV is still above $5

Wow Ari, you’re so edgy!

But there really is no size that you could take as a cutoff and say, ok, now it's big enough. It's not so clear that if you ever got to 30GB blocks they would still seem big.

There is no such innate thing as “big”. It is a relative term.
Thus the term in this context is referencing its relative size to those that have gone before it.
It would seem to me an appropriate term to use.