Said a lot since years, but still not true. And as older you get the more you'll notice that sitting on a sofa with a laptop isn't ergonomic - you'll get backache, have a limited screen size, maybe heating problems, deal with a neutered keyboard in a bad position, false height of the monitor etc; You'll buy a big monitor, keyboard and a mouse and put all on a desk, buy a desk chair and ask yourself: Why do I need a notebook if it a) isn't used as a notebook anymore and b) isn't cheaper than a comparable PC?
Back to topic: To less information for any recommendation. Do you want to compile software on it? Video editing? Will it be just a file- and media- and backup-server? Or is it just about browsing the web and writing letters? 24/7 or only powered if needed? Does size matter?
I'm a fan of buying hardware components instead of a complete PC. And I still wouldn't choose ARM today (maybe in a few years when it comes more common - today it's *IMO* more a playground for nerds).
But as you're saying it's more a "process of collecting information"…:
I'm living under the roof and summers are hot. I don't want to heat up more than necessary, and we only have one earth. So I defined a limit of 65 W TDP for the CPU. 4 cores without multithreading (4 threads) or 3 cores with multithreading (6 threads) are *IMO* enough if it's just an office PC, but if it's used for virtual machines, compilers, video editing etc. I would say that 6/6 resp. 4/8 is a minimum. Multithreading isn't something I would insist of, in fact I would prefer a CPU without it (and get more single core performance instead). Hardly available anymore.
One basic decision: CPU bundled with GPU, or a separated graphic card? A separate card gives you more options - and even passive cards exist; In two PCs I've got passive NVIDIA GeForce GT 1030, and I'm happy with them; Not all of them on the market can do 4k@60 Hz, so a closer look in the specs is required.
That brings me back to the CPU: Maybe you want to take a closer look on AMDs Ryzen 5 3600x and Ryzen 7 3700x. The newer variants (both are "outdated") are IMO still to expensive.
Mainboard: I would explicit not choose PCIe 4 because of it's power consumption and temperature; And as far I know you wouldn't notice any difference of the faster speed of PCIe 4 compared to PCIe 3 on a desktop PC.
NVMe: Yes, as long you don't exceed 2 TB (costs). But I wouldn't choose a NVME which needs a heatsink. But I would add a heatsink. I'm happy with Corsairs MP510 serie. The successor MP600 produces more heat without any observable benefit.
That leads me to "cooling it": I really can recommend coolers from Noctua. Actually there exists even a passive monster (
https://noctua.at/en/nh-p1), but what I really like: I can interchange the fans of the coolers - I can buy them separate. And there are really low noise ones, and also there are "low noise adapters" which reduce the fan speed. Of course you've got to take care of the temperature, but the combination of "lowest speed and big cooler" so far always worked for me. Having that said: A bigger case is better. And I always change the fans shipped with the case. I don't want to hear anything of my PC (and I'm sensitive).
But as all components today are fast enough: Monitor, keyboard and mouse have to be as comfortable as possible. These are the components I would never try to save money. One single monitor instead of two (less stress!), as big as possible (but not bigger than 85 cm width / 50 cm height), lite (!) curved if it's wider than ~65 cm, and more than 92 DPI. A keyboard without numberpad is a good try - on laptops most users don't miss a keypad, so you can give it a try on the desktop, too. You're benefit is ergonomic as your mouse isn't far away from the chars of the keyboard. And as rooms lightness can differ in wide ranges before you put on a light: Black keybords are not as ergonomic as white ones. To my surprise I found out I want mechanic keyboards (Cherry silent red) - maybe you want to take a look at 80% premium customization on
https://en.varmilo.com/keyboardproscenium/. I love them.
Oh my, I could write on for hours… but I think that's enough for a shoot into the blue.