As a float angler I would agree that static baits will catch more. Float fishing can however fill a niche as fewer people are doing it, it works well later in the summer especially when the fish wise up to big static baits and go for smaller particles on the drop. I'm pretty certain on the Severn for example they are hitting feeder spillage on the drop from barbel anglers so readily after a while so much so that you can get them first cast sometimes swim hopping when lucky. Water clarity is more of an issue with float fishing, I've found the clearer the better, throw in a bit of weed and it's a match made in heaven for float fishing pellet, add a lot of colour and sometimes I do wish I had a static bait out, but only fleetingly, it's more of a test of your skill when the conditions aren't favourable.
Much also depends on the water, large rivers lend themselves to static fishing, you're not going to fish well with hemp and tare or even pellets three quarters across the lower Severn or Thames with a float. Feeding is key, with big roach the loosefeed has to be compact whereas with chub and barbel they can be fed looser like with a catty, don't know if it's the same on the lead but it's something I've found applies to float. On smaller rivers everything is so precise so float is more equal with lead.
Lots of big roach do fall on larger rivers to barbel and carp anglers on lead but with float fishing I find it pays to be on top of them like wading out on the middle Severn or getting on a weir on the Thames preferably from a boat as bankside access is often limited there. Location is key with big roach like any other species but maybe more so with float fishing as you can't wait out for fish to pass through and swims need to accessible for the control of the float to be there.