Its a fact children have as much 'stuff' as adults and in some cases probably more. Birthdays, Christmas, school art projects, ad hoc gifts, pocket money spends, the list is endless. Some is educational and some not but all is precious to the child. Or is it?
Think about the 'stuff' in your wardrobe that you can't see because its squashed into a bag under several more bags and at the back where the spiders live! You don't want to throw it away but you haven't seen it in quite a while. Is it really that precious? Takes up space and adds nothing to your fabulous fashion style.
A sift and a sort of the toys in your home is likely to lose a quarter of the redundant and the broken. Its up to you if you involve the child in the decision making but bear in mind their reaction, much like yours, will be emotional when you suggest that the doll with one arm, a crayoned face, dodgy eye and butchered hair is no longer pleasing. Ditto jigsaw with missing pieces, car without a wheel etc.
Children don't like to tidy up as a rule much the same as adults are not that keen. It is so much harder when the child has no idea 'how' to tidy up. What do I mean? If the toys have a place to live - a place for books, a place for soft toys, a place for the car collection (a magnetic board is genius) then both you and the child know what is expected. Pictures on containers showing what lives in them will make it a fun game and is less confusing.
You may be a tidy person and have order in your life and that of your child. If so you are winning. If not do a calculation of how much time you spend trying to keep on top of your child's stash of belongings and how many times you trip, slip and have a nasty injury as you step on a lego corner. It's wasting time and stressing you out.
I have yet to find a single soul that finds tripping over toys a joyful and fun act. You can work on a solution yourself or ask for some help but getting it done will feel so much better.