This depends on the level of the player observing the game, compared to the players level. It's pretty common to have a strong player at a masters level pointin

This depends on the level of the player observing the game, compared to the players level. It's pretty common to have a strong player at a masters level pointing out subtle positional or tactical mistakes, but the enemy is not skilled enough to exploit those - so the mistakes do not matter at that level. This is also something to keep in mind to not get discouraged: Just because every move is terrible to a 3500+ chess engine at some level, it does not mean these concerns always apply to you at half that rating.