The question to be asked here is "are they still good bus territory?" And even if passenger numbers are reasonable, what is access like (e.g. parked cars?). I will admit I haven't used these routes (bit too far away from me for a random housing estate tour), but has anyone commenting done so, to give some idea of passenger numbers? Being aware, of course, that one person's "rammed" is another person's "never anyone on when I see it".
To take another example from elsewhere in Kent, on a pure "social strata" aspect, the Isle of Sheppey should be "good bus territory" - in fact, it's awful, and has been for decades.
Not for a little while but I did use to use the 34 from Margate to Ramsgate via Newington. Admittedly it often coincided with school kicking out but it was busy. However, I would say that there wasn't that much use within Newington, which is also a bit of a nightmare for poor parking.
More generally, I am a little surprised by the number of friends/acquaintances on the main bus routes who will always use the car to get around Thanet. One friend has a bus stop literally opposite her house but it wouldn't occur her to jump on a bus
I moved down from London so I guess I tend to think public transport first and I do get the ease and flexibility of a car so it's probably more about my mindset!