Bonjour Cathryn,

If you say "je mange une pomme le matin/le soir", you do imply "each/every". However, with "le matin/soir", you are actually saying "in the morning/evening", i.e. you're insisting on the moment of the day, whereas with "chaque/tous les...", you're insisting on the repetition of the action. So, there's a clear difference and they're not interchangeable.

I hope this is helpful.

Bonne journée !