The mysteries are still fairly good, but my frustration about the writing around the 2nd to 3rd season change was immense. That frustration, coupled with a dislike of new character Kitty (Ophelia Lovibond) and her story arc, caused me to stop watching the season for seven(!) years. I returned because COVID-19. And at the end of the season I thought "where's the season end wind-up?" They waited until the last episode to bring that in - and it felt thoroughly improbable. Just like the grandstanding between the first and second seasons, and the worse grandstanding between the second and third seasons. The person who caused all the trouble in the final episode wasn't smart enough (or together enough) to pull off something as complex as he managed.
Sherlock (Jonny Lee Miller) and Watson (Lucy Liu) are still reasonably appealing characters, but they're stuck in deep grooves in a world that only changes at season ends.