Rural and small town, often yes.

Varies with region. Some big cities (London, Manchester) seem to have good public transport although its been a while since I used a bus in either.

Sadly yes. Some bus companies are very reliable (traffic jams permitting), but there are definitely times when they aren't, and I've used rural routes where the hourly bus might just not turn up, which makes them completely infeasible for commuting or appointments.

To replace cars with buses for trips you really need them to be rock solid.

Outside of London, Manchester, Nottingham and a few selected other places, busses in England tend to be fairly dire, especially as you get out to smaller towns and villages.

Even if the routes are there, it's not uncommon for the actual busses to bare little resemblance to the published timetable.

In some places you'll get fancy live information screens which happily announce the arrival of a bus that doesn't exist, or more frequently, to simply state that the information isn't available, please check the paper boards.

Bus routes tend to be especially bad in rural towns and villages, but even in my fairly reasonably large town, it's quicker and more convenient for me to walk the 1.3 miles to the train station than try to get a bus.

If I plug in "bus" on google maps planner, it has me walk 20 minutes to a bus stop to sit on a bus for 7 minutes, versus a ~25 minute walk.

Alternatively, I could walk 5 minutes to a nearer stop, wait 30 minutes for the next bus, which itself then takes 26 minutes to get to the bus station, which is itself a 3-4 minute walk from the bus station to the train station itself.

And that's assuming the bus is on time running to schedule, and doesn't then hit traffic.

I'd also be paying £3 one-way for this privilege.

Once you're inside the TFL zone everything changes and busses are frequent, generally reliable, and cheaper.

It depends where you are, some areas have very good bus services and other terrible ones. Almost everywhere has been forbidden from having a more centralised approach and so most places are a mash of random companies with very different approaches and reliabilities.