Why do leading web studios very rarely make up on flex?

Question

Layout

I look at sites made by leading web studios. Flex is used very rarely. Tell me please, what is the reason for this?

Answer 1

Because there may be an item in the TOR: support for IE 8-9

Answer 2

Because - to make up on flexes you need talent, and they have in-line work.

Answer 3

Because in order to make websites on Bitrisk + Bootstrap (the top studios that I saw use this particular bundle) you don’t need flex :) If only they gave money and that’s it. In larger companies, as far as I understand, more modern technologies and trends are used.