I beg to differ. I'm 55.
Let's go back to say around 1994/5. I've just got a job as the first dedicated IT bod for a pie factory near Plymouth (Devon not MA)! Win 3.11 was pretty much everywhere and was almost reliable - patching wasn't really a thing then in the MS world. By then Pentium (586) was a thing but the majority of machines were 80486, 80386s were still useful. There were also the 386/486 SX/DX and DX2 and Cyrix and so on.
The planning spreadsheets were a series of Lotus 1-2-3 jobbies with a lot of manual copy and pasting and I gradually ported it to a Excel VBA job. To cut a long story short, I was running Win311 and Excel on a Pentium 75 with 16MB RAM, IDE HDD. Excel was way quicker to start than on a modern PC running Win 11 with an SSD.
Yes, a lot of things took a while but I ended up with a finite capacity plan in VBA for an entire factory that took less than five minutes per run. That was for meat and dough prep, make, bake and wrap and dispatch for 150 odd finished product lines. It generated a labour plan as well and ran totally to forecast (which it also did). Pasties, sossie rolls etc are generally made to forecast - they take a while to get through the plant and have to be delivered into depot with enough code (shelf life) for the customer (store) to be able to sell them and the consumer to not be given a dose of the trots. As reality kicked in, you input the actual orders etc and it refined the plan.
OK not the best tool for the job but I hope I show that a spreadsheet back in the day was more than capable of doing useful things. I've just fired up LO calc on my laptop with a SSD and it took longer than I remember old school Excel starting up or perhaps the same time.