If you want to keep the DDR4 and save money, you have two options. One, a cheap Z790 board like the Z790 PG Lightning DDR4 or MSI Pro Z690-A DDR4 and 12700K (skip the 13th and 14th gen, they have issues and 12700K has a good price now). Two, a B550 board with 5700X3D.

Option 2 has a better CPU for games but an older B550 platform. If your need are modest (you don't need 2+ Gen4 SSDs or many faster USB ports), it will do. Also, 5700X3D is easier to cool.

Intel option has a decent allround CPU and Z790 is a better featured platform than B550. If you're only gaming, you don't need to worry about heat and something like Thermalright Phantom Spirit 120 SE or ID Cooling Frozn A620 Pro SE is enough to cool the CPU, especially if you undervolt it (that's why a Z series board). Depending on the game, 5700X3D might still be slightly better for gaming.

Or get an AM5 board and CPU, since you're changing the whole platform anyway. A cheap B650 board, Ryzen 7500F or 7600 non-X with 2x16GB DDR5 6000 CL30 shouldn't be that much expensive than previous options...