Actually, it's NOT "much faster", and even when it is it makes literally ZERO sense to buy DDR5 at this time.
It's absurdly expensive, because it's barely even available in practically every market out there.
The performance gains are so minimal as to be almost non-existent, and in some cases given the high latency of a new memory architecture, actually slower than some highly refined DDR4. Until DDR5 becomes more widely available at reasonable prices, and has been around long enough for the latency that is always high at the beginning of a new memory architecture cycle to be optimized to much lower numbers, there is no compelling reason to buy into right now. Later, certainly. Getting a platform that requires it just to already be into the next architecture, eh, you'd need a really good reason or really deep pockets to the point where they money literally doesn't matter to you, for it to make sense.
As far as getting 32GB of memory, that also literally has no definable advantage for 99% of gamers right now. There are zero games that I know of which will even use anything close to 16GB, much less 32GB, so unless you have other reasons like scientific, artistic or productivity apps, or VMs, that can make use of that additional memory, it's simply a waste of money. If you know you will be running VMs or applications that can use it, then absolutely it's wise to get it now all at once, otherwise it's just trying to pad your stats and measure epeens.
As for the CPUs, that's off the mark as well. Sure, that i5 has only six performance cores, but that is more than just about any game will use and for those that WILL use more, it also has an additional six hyperthreads PLUS those four efficiency cores. Unless you buy into an EVEN LOWER CPU model from Intel, this is the type of design you are going to see, on all their high end CPUs now. Going to Ryzen doesn't much change that, because that architecture also has a "preferred core" architecture so even though it's a bit different, it's also a bit the same. And regardless, much as when some major architectural changes have happened in the past, you can't simply look at cores or clock speed and assume you know how that affects actual real world performance because you'll be misled. This CPU is perfectly fine for any gaming system and while it's "only" an i5, it clearly outperforms the i7-11700k from the last gen in both single and multi-threaded operations, so to act like this is some weak CPU choice is absurd.
In fact, this i5 outperforms last gens i9-11900k in both single and multithreaded performance, so in reality it is a good as the BEST consumer CPU Intel had to offer prior to Alder lake. Period.
https://www.cpubenchmark.net/compare/Intel-i5-12600K-vs-Intel-i9-11900K/4603vs3904
Certainly, in ALL generations, buying a higher end CPU is usually going to benefit performance. That's why they are higher end. But they also cost more and depending on the specifics of the intended use, "better" doesn't always translate to seeing any difference in the processes or use case for the user in question. If what you are doing can't take advantage of the additional cores, threads, instruction compatibility or clock speed, because it is not optimized to do so OR because it's bottleneck is elsewhere, then it will be a waste of that person's money until such time (If ever) that area of concern is addressed by the application, OS or game developer.
There are ALWAYS things you can improve, on any kind of build. But spending more doesn't always, in fact, often, mean you are going to see an appreciable return for that additional investment.