It's been growing in popularity. I think the low cost, low barrier to entry, slower pace of play, and ability to use old cards makes it really attractive as current, new magic is growing ever increasingly more expensive, faster, and less attractive.
One of the cards from the recent Final Fantasy set was one of the keystone, linchpin card to the top meta deck in the Standard format, and it became very expensive. It's cheapest, regular printing reaching upwards of $60/ea, or $240 for a playset. WOTC made a
statement in September saying it needed to be banned, would probably be banned, but weren't actually going to ban anything until November.
This put competitive players in a really tough spot. There were still events to go grind.. The card was still legal for the time being.. But the price immediately started dropping. (It now sits around $25/ea) Do I cash out now? Or hold out? What if I cash out now, and then they don't ban it? The price will go back up as people rush to re-buy!!
Bad feels all around. A pauper card gets banned, and it's like
"Oh dang.. I'm out $1.48 for that playset of Deadly Disputes.. Good thing I didn't spring the $2.50 for the foil playset!"