Is this a good build for gaming?

CGDirector.com Parts List: https://www.cgdirector.com/pc-builder/?=6Mh0e

CPU: AMD Ryzen 7 5800X 3.8GHz 8-Core Processor ($448.62)
CPU Cooler: be quiet! Dark Rock Pro 4 ($84.90)
Motherboard: MSI X570 Tomahawk ATX AM4 ($291.38)
GPU: Nvidia RTX 3090 24GB - EVGA FTW3 ($3290.00)
Memory: 64GB (4 x 16GB) G.Skill Trident Z Neo DDR4-3600 C16 ($364.99)
Storage PCIe-SSD: Sabrent Rocket 1TB NVMe Gen4 M.2 Solid State Drive ($149.98)
Power Supply: Corsair RMx Series RM750x 750W Power Supply ($132.67)
Case: Phanteks Eclipse P300 ATX Mid Tower Case ($161.99)
Total: $4924.53
I do not really have a budget as of right now.

That build is superb for gaming. You don't really need the 3090 unless you have a crazy amount of budget to spend. Look into something like a 3080 or 3070 to save some money. For Gaming you can also get away with less RAM, 16 or 32GB will do just fine.

If you go for a beast like that I would change the PSU to 850w and add an extra 1TB SSD

Edit: and I would change the CPU cooler with a liquid cooler.