The coding interview itself is an immune system against the surprisingly large population of candidates who have long resumes and can talk a big game but not actually perform. (I didn't believe these people existed either, until I started doing phone screens).
It's also a way to recognize smart people who will do well with whatever they're given, even if they're underutilized or in a different domain at their current job. Tech companies are typically hiring more for this than for tech stack or business domain similarity.
You're trying to measure how they'll perform on your work before you hire them? That sounds like you're trying to get free work from them. (Just a note.. this is on the words you used)
> recognize smart people who will do well with whatever they're given,
How does a take home coding test that is limited on time, and their own time + stress indicate that they are in that category?
I wish the hyperbole about trying to get free work during an interview would just die already. Nobody is getting free work by interviewing applicants, interviews are costly to most companies, but necessary to grow the team.
Just because interviews take time and are difficult and scary doesn’t mean someone is taking advantage of you. Try to put yourself in the company’s shoes — they have to evaluate you one way or the other. How would you do it?
A time limited stress test is extremely effective at identifying certain kinds of performers. Obviously being able to solve problems fast is an indicator of a certain kind of smart. This doesn’t identify all smart people, and nobody claimed it did, that’s why a coding test is almost always one part of many in the interview process, and people routinely get hired when passing some parts without passing all the parts.
Most companies have 4 sessions : 1 HR phone, 1 tech phone, 1 tech onsite, 1 HR onsite.
But bigger companies (i.e. bigger salary) increase the 'tech onsite' up to 4. Some companies replace one of the tech phone/onsites with a take-home challenge.
If you want more money, you gotta beat the other 100 people who also want more money. Simple case of demand and supply.