It may have accelerated its reach a bit in some countries like the UK because Stonewall felt they needed a new cause but I think it would have still happened to some extent without marriage equality.

I think some of the timing is coincidental rather than straight up causation. Around a decade ago is when social media really blew up and people started becoming very 'online' especially the youngest generations. That's what has fed much of it in conjunction with queer theory being pushed via higher education. Speaking of higher ed, in the UK at least, it's also the time frame in which universities have ceded a lot of power to students because they became paying customers via high tuition fees. If education were still free I think more of the crap that goes on would have been nipped in the bud.

It's also worth noting that orgs like The Beaumont Society and the older transactivists like Burns and Whittle have been around much longer than most people are aware of, lobbying governments and influential people. I'm speaking from a UK centric perspective here but much of the groundwork was already laid before it all went viral and anyone realised the significance of what was being done.

In short I think it's been a perfect storm situation with no one factor to 'blame'.