Exactly, I doubt anyone here gets stuff at LFS anymore unless they have money to burn. It is just so much cheaper online.
As for fish, that is what the LFS is for. They will always stay in business if they offer stuff the big chains don't. However even then you have to go online for some stuff depending how good your LFS is.
Each has it's purpose, online is for cheap parts and less common fish you don't mind paying an extra $50 on shipping.
LFS is for when you need something right now and it's specific stuff the big chains don't carry like certain foods and such. Sometimes it's not worth it to order online because shipping is more, so you grab a bottle of prime at the LFS or something. They are also good for fish, obviously. And if it's a good LFS they will have some nice fish. Things like filters/tanks I do not buy at the LFS though, way over priced.
Chain stores, good for cheap new tanks when they have sales. Same for filters or if you need one right then and can't wait for shipping. Food, not so much it is fairly over priced in my experience. Fish, not so much either except for some of the more common things. They never really have any oddballs. I did get some of my Clown Loaches and my Oscar at my local Petsmart though. They were cheaper than the LFS and the fish are doing great. However it's rare instances where most of us will buy fish at big chains considering they hardly sell anything out of the ordinary.
Each has it's place and will stay in that place as long as they do it correctly.