Does Riot take suggestions from players anymore?

They tend to take suggestions on aesthetic things, like skins and splash arts.

They sometimes take feedback on reworks (e.g. keep Y in X's kit after their rework.)

They very rarely take suggestions or feedback regarding balance (e.g. X feels too weak / unrewarding to play.)

They practically never take suggestions about the design of existing champions (e.g. X is no fun to play against because...)

Does Riot take suggestions from players anymore?

LoL is the most played game in the world at the moment and it has a monstrous player base. For every suggestion Riot can realistically act on, there are millions of others they simply cannot, so they're never really going to appear like they do take suggestions now.

Also - most players seem to give suggestions regarding game design, which has a particular set of issues. With textures, models, animations, rigs, programming - it's easy to prove what you did is what you did, and what Riot owns in that regard is a pretty tangible thing.

With game design though, the field specializing in actually putting everything together and making champion kits: what they work with and on are ideas. And designers can run into some pretty big problems if they steal someone's ideas, so they have a serious legal drive to ignore the community. With LoL's player base, probability pretty much states a slew of LoL fan somewhere out there came up each thing in the game. The further a designer can separate themselves from random fan #24753 the easier it is for them to prove the ideas matching are a coincidence and theft was not involved.

Check the pbe forums Statikk and Rep have polished Skar, Garen, and Darius into nice looking champs because they've been working with the players in their reworks as compared to Morde where CerT has basically gone dark and is doing as he pleases.