How about a Swiffer ?

A swiffer is a help but it doesn’t seem to get larger particles, not dust, which come from who knows where. Also, any small lego pieces the grandkids happen to accidentally drop and which slide under the sofa. Once something is under there, it’s a massive job to lift the sectional pieces. They also don’t slide.

We control clutter and do daily normal cleaning as well as frequent weekly vacuuming, mopping, dusting, etc. in between regular vacuuming, I use a Robot vacuum.

Its not a huge deal, just temporarily irritating whem I shine a flashlight under the sectional and see how much debris is under there.

Though I haven't used it yet. My vacuum came with an attachment that cleans under the fridge. I don't see why it wouldn't work under a sofa. If you can find the attachment to fit your type of vacuum.

Re moving your sectional - there are products EZ Movers, Magic Sliders, etc, they come in different shapes/sizes - very smooth on one side - peel/stick adhesive on the other side - put them on the bottom of furniture legs - makes furniture much easier to move on any flooring type - also reuseable ones are made without the adhesive back. I have the peel/stick ones on most of my furniture - makes them easier to move for vacuuming & accessing the outlets behind the funiture.

A microfiber duster with an articulating arm, extendable handle, might be all you need. Under $20.

I took the legs off my sofa and now it sits flat and I don't have to clean under it.. It now slides easily, too.