Why do companies use terrible job application portals like Workday?

Almost nothing in your IDE is "best in class": there are easier terminals, quicker searches, smarter diff tools, quicker editors, faster test runners, etc. What makes your IDE good is that all these mediocre parts are integrated, understand each other, can be used without learning yet another tool, and there's a big community sharing know-how about taming the Frankenstein's monster you chose. Still, many parts are clunky and will frustrate people who use it once every few years.

An ERP like Workday is the IDE for an enterprise (and a safe default like VSCode & co). Any single component is always worse than an entire startup laser-focused on that problem/process (e.g., ATS), but for most business processes, "satisfying" is much better than "optimizing". When a business grows, the range of problems they need to address increases rapidly, like the surface area of a balloon being inflated. "Good enough" is good enough until it becomes so painful as to become a top problem for the CEO or the HR Head, and "which ATS we use" never crosses that threshold. Yes, getting new talent is important, but ATS friction is not a big contributor - Google/Netflix could use anything, and their pipeline would not change in either direction, so the main levers are elsewhere.

Prob a few reasons

1. Cuts down on low-effort applications

2. Gives full functionality for a large company

Same reasons Google and other have their own torturous processes

First you have to find out who is really desperate to work for a company

And a lot of big companies are GREAT places to work for certain types of people

Most people, prob

And you might not even have to do an application unless and until you go to convert to full time

So you have to fill out the app, but you're already hired so it's worth it

The real problem with technical recruiting that creates a bunch of nasty feedback loops in the system is recruiters and HR not understanding the technologies they work with and not having the engineering sense to talk with candidates for 5-10 minutes about their projects and see if they're full of shit or not. The only thing 98% of them can figure out how to ask is "How many years of experience do you have with ____ technology?"

Workday is cheaper, right? I think that's the ultimate answer.

Money, compliance, vendor lock-in, and/or obliviousness by the decision makers.