I would be agree with you if it wouldn´t be for the post that Plarium posted in this forum in 2019 with the "road map of 2019". In that map they promised new factions, void tower, new clan boss, tag arena and since now, half of 2020. we didnt get any of it.
The game is good but disappointing and at certain point you fall in the routine and there is no fun in it. See, the fact that RNG exist to get champs is fine for me, if you are lucky like one of my friends in the clan, you get with 10 ancient shards martyr and vizier while others got just 10 bad rares. It is how it is and we dont blame anything or anyone. HOWEVER, the lack of content has just one part to blame and thats Plarium. Its not normal that in half a year approx that the game has of life, there is nothing more than just a clan boss to interact with your clan or that we need to pray to get some books time to time in the clan boss.. (void tower from the rumours that I heard was bringing book farming options).
About the Battle Pass, you are right, it was an amazing idea. Plarium seems like they will bring even the 2nd Battle Pass with great champs, but why it takes so long? because they want to make sure it brings all the champs inside? well just make a pre season battle pass with very little rewards or something while the big one comes so you make people happy for nothing...
I think more than lack of staff, they have a lack of marketing and proper knowledge of how to keep a base of players in a game happy. Even tho, just little things like add these new features they promised in 2019 would make the game amazing, they have a diamond in their hands, now they need to make sure they make it shine properly.