Well, they have a more focused cone of airflow than a case can.
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Focusing the front fans with drives / cable / clutter is a good idea. It pierces through the clutter between the front and the MOBO to be more effective. I have 3 fans on the front that have to fight though the 5 disks to get to the MOBO. Besides this though I have 2 on the air cooler which are more effective than the single fan that ships with it. The air cooler is basically a radiator though not as tightly packed it's still offering some resistance to the fans The exhaust fan on the back is the easiest for resistance with just the grill pattern to deal with. Top is mesh but also filtered with 2 fans.
I've been using them for years and I've tried the Noctua's and they're just as effective for 1/2 the price. When I picked them I was comparing the stats - db / rpm range / CFM / reviews from actual users. If they keep my 12700K cool to room temp they'll surely keep your system cool as well. Maybe you'll only want to use 5 to start w/ 2 on the CPU tower / 2 in the front / 1 on the back and see how the temps are. Should be sufficient enough even with the RTX in the case since you're only running 2 operational fans currently.
Upgrading the cooling tower will keep the CPU running smoothly under load more efficiently. It's about performance and acoustics. If you want even quieter load it up w/ all the positions filled with fans as they work in conjunction with each other to keep the airflow optimal based on the temp sensors.