Having worked at many companies over the years as a web dev, I can confirm these sites are held together with more tape and zip ties under the hood than you'd think!
15 years in IT OPS before switching to programming. Can confirm most IT infrastructure is held together with duct tape and the occasional prayer meeting in the data center.
They've been shit for 30 years, do you really think they'll suddenly grow a conscience and care a little less about money so that they can make great software? Come on now, really?
Last week our SaaS vendor went down for a good 2 days. The vendor the company spends about 1.1 million per year to keep running. It doesn't bother me really, just means I can concentrate on other things(and I get paid either way), but its amazing what other companies run as their infrastructure.
Makes me feel good with my equivalent potato servers.