Maybe a diversion from American politics, COVID-19, and the upcoming presidential election, I am not even sure but I found Bly Manor intriguing. As an American who has never visited the UK, I am not familiar with the regional accents. So, I didn't pick up on poor accents. My take on this series is that the ghosts were simply a vehicle to explore the complexities of love.
You did a thorough fair critique. Perhaps Flanagan should have went with a completely different storyline. It is too easy to compare Hill House and Bly Manor. Hill house was superb. Often, It is a challenge meet and exceed expectations.