Recruiting is a time consuming task for all involved and for you to casually waste peoples time in that manner is horribly disrespectful
The job candidates didn't create this problem.
Most companies disclose what their process is up front and you're free to opt out at any time. Intentionally wasting the time of the recruiters and engineers at companies you don't want to work for just to "practice" just seems really rude
That's funny. You should do stand-up.
The argument cuts both ways. If the company rejects most people they bring for an on-site interview, then they are OK with wasting a lot of people's time. It is the company's responsibility to screen their candidates better.
Among the FAANG companies, 7 different recruiters contacted me this year (including multiple recruiters from the same company - for different divisions). I didn't apply to any of them. I got past their screen and they brought me on site.