I think this viewpoint is common from senior engineers but not entirely merited.
(FWIW, I am also a senior engineer, and I have seen this play out from both sides of the table.)
Sometimes folks overestimate their value as senior engineer for certain types of companies, and under-appreciate the risk companies take in hiring an employee. Large companies, for example, generally do not need yet another L6+ that cannot get their hands dirty. They usually have plenty of folks that fit that role already. Additionally, senior engineers are expected to mentor junior engineers, and doing so often requires whiteboard technical skills.
I cannot tell you the number of L6/L7/L8 interviews I've done where it was clear the person had no idea how to write simple algorithms, or put together a basic design. They may be great (or not) at the job they have been doing for years, but that sort of information is not accessible to the interviewing company. If the skills existed, it is a red flag if the candidate let them languish. Or perhaps those skills never existed, and that's a very large risk the company ($100,000s/year) is taking, especially for companies (cough FANG cough) that have a "you must be smart if you made it here" attitude around letting people go.
If one agrees to interview somewhere, it should come with the understanding that it is a mutual exchange. The company is not doing the interviewee a favor, and the interviewee is are not doing the company a favor. Both sides are expending work, which involves some tradeoffs and annoyances. As an interviewer, throwing in a technical question early is an easy sorting check to make early in the interview process before it gets into the nuanced details around role fit.