Whiteboard coding is nonsense for any other purpose than weeding out the truly incompetent.
Past that point, it's a crapshoot. I think homework / portfolio are the most reasonable evaluative tools, but there are some legitimate downsides there around the bias it can introduce into your process, and the potential candidates who may be turned off by it.
Things worked out for me, but not before I had some serious self doubt.
So, stick too it. You (probably, I don't actually know) are good at your job - don't let the nonsense process convince you otherwise. Look for companies that share your viewpoints.
Absolutely. Asking a person to produce correct code with just a whiteboard/pen/notepad is like asking a surgeon to do with just a kitchen knife. An intelligent code-completing&checking IDE, a debugger and the Internet should be considered parts of a developer's body nowadays, restricting usage of these makes just as much sense as restricting usage of glasses for reading or requiring people to get to the office without using personal/public transport vehicles.
If an interviewer scolds you for writing whiteboard code that will cause a compiler syntax error, red flag, time to bail out. This is now how they are supposed to be done.
Properly done I might go against the grain saying I prefer whiteboarding tests over take-home tests. With whiteboarding, both parties are at least with equal time investment and a higher level of transparency. And once the interview is done, it is done. No thinking about how to schedule your next few days around finishing unpaid work for a company that you may have a chance with.
In some engineering fields, I'd expect that such inconsistency in hiring practices would result in hiring someone that causes a huge accident.
Dark version: software interviewing would not be this broken if most bugs or mistakes would directly result in a person's serious injury or death.
I've been in software dev for a decade but don't have a comp sci degree and it shows a bit. Every few years when looking for a new job I stress and try to re-learn these algorithms that I only ever need to know for these interviews.