As said, hard to know how much of an immediate difference you'd notice.
For the future though, that motherboard probably has more longevity to it than your current one: 4 DIMMS DDR5 192 GB max vs your current 2 DIMMS DDR4 64 GB max; 4 M.2 slots vs 2; a PCIe 5.0 GPU slot vs PCIe 3.0; WiFi 6E vs 6...less impressive USB options on the back though.
So even if you don't notice a huge boost now, it could be that in a couple of years you'll appreciate the upgrade options you have; whereas if you stick with your current setup, you might find your board wanting in a couple of years and end up having to pay to upgrade.
Plus of course if you take the upgrade you could sell your current CPU + motherboard + RAM as a bundle and make some money (once you're happy with your new system), or pass it on to somebody else free for karma.
I'd say, if you think you really won't want to upgrade any part of your system during the next three years then it might not be worth the hassle. But if you might do then this is probably a worthwhile thing to do now if you're being given free parts.