IMO, LC (and similar) aren't a bad choice for the interview process. The problem comes when it's used as a silver bullet solution. Most seniors that'll show up to an interview are probably working and simply don't have the time or will to grind LC.
Also, SWE is a highly movable profession, where being more than 5 years on the same place is unusual. So every ~5 years you have to polish your CV, grind LC and basically restart learning all computer science concepts you haven't used in those ~5 years, without feeling burnout or dismay.
Also, SWE is a highly movable profession, where being more than 5 years on the same place is unusual. So every ~5 years you have to polish your CV, grind LC and basically restart learning all computer science concepts you haven't used in those ~5 years, without feeling burnout or dismay.