S1= secret agencies, mysterious experiments, physic powers,the dark subject matter of the abuse of these subjects to exploit such powers, and the thrilling escape from these nefarious machinations.

S2= we get to explore the other world, foreboding air of danger throughout, development and growth of the gang. Similar tone as the 1st season and closes it well.

S1+S2 fits and works together.

S3=budget feels halved, core group split up for nearly the whole season, big CGI monster that looks at home in Resident Evil 2 or The Evil Within 2 video game, contrived setups , poor consistency , cheap guard costumes and lazy jokes.

Even worse thing is that they somehow made the characters flat one-note archetypes, with romances shoehorned in. It's quite sad for what S3 has turned out to be.

Guess it could be summed up as if it was made cause fans wants a new season (naturally since S1 and S2 was good) , and the producers and creators decide to chase the money that comes with that. Rather then working at it until they have something interesting to show, they just went with a hackjob of various 80s cliches.

And of course in analyzing why the drop in quality is so dramatic, we also need need to look at the pressure the suits must be pressing on the showmakers. Imagine an even greater fall in Netflix stocks if S3 was not made in time .....