I feel after Lorca died, the whole military structure and discipline and authority faded more and more, and I didn't realise how important that was to a series feeling like Star Trek. By series 3 the crew just feels like an obnoxious work clique who just do whatever they want without any real consequences.
What Discovery writers have forgotten is that you have to ground it in something real and with logical consequences, or this leads to decisions that just make it increasingly frustrating and unbelievable (which says a lot for a ship in an alien world).
Picard would never have promoted Ensign Wesley Crusher as Captain over all the other more qualified bridge crew (who've actually taken Command training) because that would have been completely fucking mental and ridiciculous. Discovery though is so far from believability or grounding in reality that they can do the same with Ensign Tilly without raising objections.