I'm guessing they probably could not have scaled as far and fast as they did without AWS. To me, this scalability is the cost of doing business as a younger growth company. As your workload becomes more predictable, this additional cost becomes less beneficial. I've come to see that often companies say they are saving money by moving off AWS, but much of these saving come as part of rearchitecting or optimizing their systems.
My first computer was a Gateway2000 486/DX 33MHz. I think it was the same one that Linus developed on. It had a programmable keyboard, and a 14.4 modem. You had to enter the video card clock timings manually to run X.
I installed the SLS linux distribution on about 50 3.5 inch floppy disks. I think disk 33 was corrupt. Programming was such an adventure back then. I miss those days.