FWIW (= For What It's Worth), there is some minimal interest from at least some national chess organizations in at least a handful of chess variants, especially bughouse. The USCF runs a bughouse event for children annually, I've seen on the internet (the USCF set up a committee to look at chess variants some years ago, too). If I recall correctly, FIDE includes at least the rules of Fischer Random (also called Chess960) on its website, for anyone interested in organizing or playing such - though I don't think FIDE supports such people otherwise, at the moment. An observation: my Ottawa club holds at least one unrated/fun Fischer Random tournament a year, all in one night. A couple of us hope for Seirawan Chess night(s) too, but additional equipment (hawk & elephant pieces) is needed for that (or, the ugly solution of wrapping elastics around 4 extra pieces might be used). The use of, say, 10x10 boards is out of the question for an established club that's already invested in all 8x8 boards.

A problem for the Canadian chess federation (CFC) is that they've never had much in the way of resources (perhaps typical of many national chess federations), and so funds & efforts are reserved just for chess. Nevertheless, a bughouse event for children is now held often each year at the Canadian Youth Chess Championship, though it's not official CFC policy to do so, unlike for the USCF. Organizers sometimes totally independent of organized chess are already holding several bughouse events across Canada each year, sometimes with cash prizes.

Besides bughouse, the other chess variant that seems most popular at the moment, especially on the internet, would be crazyhouse. It is like Shogi, and since it would otherwise need extra pieces or special tiles to play over-the-board (which many people do), the internet is especially useful for playing crazyhouse.

In a seperate thread on CVP I gave a link to statistics for Free Internet Chess Server (FICS) circa 2015, and for more than 15 years a steady average of about 2% of all games played were for the multiple chess variants offered (the rest [98%] were chess games), with over half of these being bughouse games played, and, for much of the remainder, crazyhouse was played. That might be an indication of the largely global trend at the moment for the relative popularity of various chess variants, and an indication of the percentage of chessplayers who may also play chess variants (i.e. 2%). There are 605,000,000 adult chess players globally, FIDE estimates (including casual players), so that works out to my estimate of 12,100,000 adult chess variant players globally (including casual ones), if one is to be consistent with FICS stats.

Also fwiw, anyone who like me has played chess seriously and kept track of the cost of their chess tournament entry fees (not to mention chess books & equipment, plus any travel, lodgings & dining out costs) vs. what they win back in prize money over any number of years will eventually see that tournament chess is a losing investment cash-wise for the vast majority of tournament players, including those who reach master level (like I did). Still, people play lotteries all the time in spite of the odds, though from customer comments I've heard when near lottery vendors, many seem unaware it's a losing investment; at least lotteries normally have more respectable prize funds and cheaper fees than for chess tournaments, though. Chess players might take playing just chess by itself less seriously if they considered all that at some point, or did so more often.