If you use the simpler examples, with just the pieces involved in the tactic on the board (plus Kings, of course) I think it’s a good way to teach kids how the pieces move and their power. I’m pretty sure I learned Knight forks before I could play a whole game. Same with bishop/rook/queen skewers on a relatively clean board. Then later on, with a fuller board, you have an eye to notice the tactics.
The problem with many endings, is that nothing “exciting” is happening in the mind of a small child. K + P vs K, and K/R/P vs K/R are extremely valuable, but many adults find them too boring to study. Then again, it might just be. I’ve played chess for years (peaking at around 2080) and botched plenty of R + P endings, but I’ve hardly ever missed a Knight Fork!