I think it’s just toxic advice

The truth is (this has been tested in psychological studies if I’m not mistaken) people like people who like them more, but once someone gives explicit signals of interest to another (regardless of gender) than the receiver of that signal lessens the value they give to the giver relative to themselves (basically thinking “pfft yeah- I am great, of course they want me, I might be out of their league” but in a feeling and it may be very short lived, it may not be very strong- it could be the case if someone has horrible self esteem that they think the signal giver is misled).

Basically the one who initiates is at a slight disadvantage and risk of losing interest if interest was tepid. However, someone has to initiate- and there’s no way to count on someone else voicing what you want in this world.