[Wigs]

probably because Vaughan with it's (less than 4 year old) subway stop/multi-modal facility with a direct connection to downtown Toronto and median housing price of $1.2M (CAD) is a tad more valuable than Plano lol
I don't think Plano is building 20,30+ storey condo towers en masse.

personally I find Vaughan to be boring and generic AF, the only redeeming quality is it's home to the largest theme park in Canada, Canada's Wonderland lol
that and it contains 95M sq ft of (mostly light) industrial space.

But it is still growing quite quickly (est. pop 340+k) now that it has direct subway access to downtown Toronto. With high growth rates and property values comes high speculation by vultures.