I work at a well known SV tech company with about 3k ppl and we got over 50,000 job applications last year. Code interviews suck, but they're a scalable way to assess skill with minimal bias.
A fresh grad is expect to be able to solve ~medium problems.
Someone with ~2 years of experience is expected to be able to solve ~hard problems.
Someone with 10 or 20 years of experience is still only expected to be able to solve ~hard problems.
The standards for a more experienced candidate are of course higher for other attributes: Leadership skills, communication skills, etc.
And if you would suggest they learn them what would that person be gaining that they lacked before?
"Skill" is probably one of the least valuable metrics of a given hire's performance over time for an employer.
Yes, being able to effectively select for the people most likely to develop a competitive non-extant algorithm is an important metric for certain employers that skill tests will assist with. However, it's as niche to general society as academic studies are.
This is not to say that it's unworthy of practice or attention. In some cases, it's absolutely justified.
What I'm advocating for, however, is skewed towards the broad middle of employment cases - people who are competent, able to solve most day-to-day problems, and not adverse to new practices.
In most cases, people aren't looking to advance the knowledge of a particular field of study. They're just looking to solve problems for their day job while earning appropriate compensation. The employer gets a satisfactory advancement of their capabilities, and the employee gets to enjoy a quality of life they're used to.
The "broad middle" is much messier, but also easier to filter for. As a hiring manager, I would look for people that are A) not obvious assholes, and B) likely to improve my team's performance in some measurable way.
In other words... Company X, which lives and dies by having the absolute latest technology available to humanity, may well need to use code interviews to even establish a baseline performance metric. Company Y, which is just interested in appreciably improving its market share versus a wide cohort, is probably better served by "softer" hiring metrics.