My Athlon 1100 was barely a third tdp at 60watts, yet was perilous to install, broke one (almost $1k, in 2001 money!), and then on the replacement had a 6500rpm screamer jet engine under my desk sitting on mobo that barely supported it and which could fail and kill my 1core cpu at any point :0
25 years ago I never had to wonder if my GPU or CPU cooler will fit the case, clear the RAM, or the HDD cage, if I have something to prop the GPU against so it doesn't sag, if the PSU power cables are fine or I need some adapter and if the adapter can cause a fire if not installed perfectly, if I can access the SSD slot after installing the GPU. That's before having the components in hand.
Installation brings new challenges, LGA sockets are fragile and generally unrepairable, the need for massive coolers leaves little room for maneuver in there, I need to replace the backplate and the general installation procedure is a lot more involved, many of the good thermal pastes are a pain to apply, and so on. The BIOS/UEFI is a jungle now but one you have to navigate to avoid issues introduced by manufacturers pushing setting to the limit in the default profile.
Nvme drives just plug in on mobo and take zero space. I don't have to navigate and bend and fit massive ribbon AND power cables from one end of case to another. 3-4 Nvme fit onto mobo basically invisibly. Want more - cheap easy riser card.
3-4 3.5" PATA drives with ribbon AND power were just fun times / exercises in masochism! And of course different types of ribbon cables, and pins on hard drive begging to be bent, and master / slave hardware settings, and some cables could burn things if plugged in the wrong way around and you had to pay attention that red line on cable aligned with tiny pin 1 on drive. And after a while or if you bend it too much that ribbon cable will give you fun intermittent errors.
Power supplies came with random assortment of built in cables you had to tuck whether you used them or nit. Now you pick and plug in cables you need.
Separate audio card and modem and network card, so definitely had to worry if I had enough Isa slots etc. Now mobo does it all. Maybe even a worthwhile integrated gpu - my 8845hs with 780m does ridiculous amount of gaming. Compared to a 2d card PLUS a 3d card and pass through cables between them - did we forget about those?? :-)
Absolutely did have to worry if my after market cpu cooler will fit back then. Perhaps with stock coolers ones we didn't but I think same is case today.
And I'm just not ready to accept the argument that thermal paste or BIOS were somehow better in 2001 without some solid evidence :-).
Well, it kinda depended on the CPU. And then sometimes the motherboard.
On the Intel side, P3s had a pin on Socket 370 to signal an immediate halt/shutdown. You could probably still damage the CPU, and I'm willing to bet a lot of the cheaper motherboards wouldn't respect it. But plenty did, since S370 needed other changes to support Coppermine anyway.
On the AMD Side, Athlon XPs and Morgan Durons did add a safety mechanism similar to the Pentium 3, but since the Thunderbird and Spitfire Durons did not, it was far far less supported.