OK, so, turns out the benchmarks I was looking at were a bit out of date. The current AMD Ryzen 9 9950X3D (or 9800X3D) quite recently released is a bit more than three times faster than my current CPU on most benchmarks. And, since the options were to spend a few hundred bucks to double my RAM or spend $1300 for a new motherboard, CPU, and RAM (but newer RAM is cheaper than RAM for my old motherboard), I opted to get all new. Three times the performance feels worth the hassle and expense.