In response to your request, Kevin Eades, aquascaping in Russia is quite developed in Moscow and St Petersburg, although I gather there are very active hobbyists outside those upscale cities. There is at least one quite good bricks and mortar store in Moscow that specializes in aquatic plants and associated equipment and supplies. I wish it had higher end items, but it's great to have access to what they do sell. Other pet stores also cover the fresh water aquascaping hobby pretty thoroughly without the exclusive focus on it. However, I get the impression that salt-water has got more followers and choices available.
The bulk of retail is through websites that deliver, but there is a sort of market that I have yet to visit where several outlets operate under one roof. All the major brands are available, although availability for any particular thing is seldom guaranteed. If you find what you want, you'd better grab it. It's also wise to get critical replacement parts for things well before you need them, or else have functional duplicate equipment. (I find that aquascaping in the urgency of its demands falls somewhere between hydroponic agriculture and an ICU.) My new tank and cabinet were made to order by a local craftsman (he deserves that title). So, lots of options, but often you need to react quickly or be ready to make substitutions. The only thing I was forced to order from outside Russia was a CO2 regulator. Only CO2Art had them for Sodastream canisters. You can get CO2 in large tanks (2 liter and 5 liter), but refill is limited to a handful of industrial places that are hard to get to and have a reputation for being difficult to deal with.
The online community is certainly there with forums, bloggers, YouTubers and everything you would expect going on all the time. What seems to be the biggest challenge is finding rocks for hardscape. They are around, but the selection seems to be depleted quickly so that it's hard to find a set of nice, large stones that match. In the end I may take the easy way out and work with wood.
It may be of interest that what propelled me into the hobby was a visit to a local botanical garden, which was started during Peter the Great's reign to grow apothecary plants. These days it is a well-arranged garden with beds of flowers that change with the seasons, greenhouses, and a tropical conservatory. By chance, on a visit I came across a display of aquascapes there. I was floored and immediately wanted to do something of the kind myself. Since then, slowly and falteringly, I've been at it.