Declutter your living room and encourage new ways to play by getting onboard with 'toy rotation' - which means only having a few boxes of toys out on display / within reach at a time. The rest are stored out of the way, but the storage must be easy for an adult to get at (in 'ready to play with' containers).
Every Saturday morning (or whenever suits you) swap the toys which are available to play with.
The result is 'new' toys appearing each week to interest and engage, whilst your living space is less cluttered with toys.
The picture above shows (some of) the 'post-Christmas toy mountain' corralled into baskets and boxes we already owned, which is what you need to do first.
I sorted the toys into: vehicles, soft toys, books (Christmas themed at the moment), farm set items, scarves / dress-up, wooden blocks, colour sorting toys, puzzle toys, big vehicles, balls and dinosaurs. Musical instruments, play food, random sensory stuff, the wooden workbench and dolly in the pushchair also feature (but were being played with when I was trying to take the photo). At least half of the toys pictured / mentioned will be put away. Any unwanted / outgrown / really irritating toys need to be put aside to pass on / send to the charity shop.
If you find that some toys are not played with, even when they are 'available' then that's a good indication that they could be passed on to a charity shop.
If you find that some toys are absolute favourites (Duplo / Lego in our house) then leave them out all the time. We always have a box of books available, but a manageable number of them (not a pile that is too heavy to lift to get to the ones at the bottom of the pile).
Do a version of 'toy rotation' that works for you. There are plenty of detailed toy rotation rotas and toy rotation charts (and probably even toy rotation apps) online if a regimented approach would suit you better.
I like the 'relaxed' approach to toy rotation. Setting out just a few 'new' containers of toys each weekend and removing others, ensures toys get properly played with - and there is much less tidying! Once you try toy rotation you'll wonder why you didn't try it sooner.