I'm an anti-bus extremist. ( I've even considered regsitering BanTheBus.com and doing an over-the-top static anti-bus website. ), so take what I'm about to say with a pinch of salt. Also note that my post applies to non-space-age. Space-age changes the gameplay fundamentally, so this really only applies to factorio 1.1 or 2.0 with space-age disabled. Gleba in particular breaks the JIT model. ( Fuck Gleba. )
Busses are the opposite of good factorio factories. They undo a lot of the benefits of a healthy just-in-time (JIT) manufacturing, by encouraging massive amounts of buffer (belt-buffer).
They also encourage people to anti-learn fundamental principles. You often people do "starter-busses" with 4 lanes of iron plates, but only fed by one actual belt worth of smelting. Then people look for all kinds of "balancing" solutions to try to alchemize one belt into 4 belts.
They encourage massive amounts of over-spend on expensive splitters to keep "balancing" the bus to make it look neat, over actually just focusing on what needs to be built.
Spaghetti on the other hand is much better for actually getting to the end-goal. Start by placing what you want to build, then look for what it needs. Work out how to feed it by any means necessary. If you dont' have enough input, then build more of that input. Then repeat as necessary.
There's no such thing as too much input. With short belts (even direct insert where possible), buffers are kept to a minimum, and any "overprodction" is stopped at source, because assemblers don't produce if they have nowhere to output into.
The biggest classic beginner mistakes in factorio are:
- Sticking things in chests. Even worse, trying to "maintain production" by picking up those chest contents. ( This comes from an RTS mindset where "idle" workers are a big sin. )
- Trying to increase throughput by replacing yellow belt with red belt when their yellow belt wasn't saturated.
- Looking for guides and discovering "The Main Bus".
That last point is so common, and not only does it take away some of the creativity of the game, but busses are inherently a bad solution that makes all bases look the same, and produces a mediocre result.
Look at how speedrunners are able to complete the game on default settings in sub 2hr30. They're not producing oodles of red belts. They're not producing main busses. They're not even producing railways. They're hyper focused on what's actually needed, which is very little indeed.