Why do London buses stop so frequently?

The hypothesis “Why do London buses stop so frequently?” This question had been bumping around my head for a few weeks now. Since moving, I take the bus more often than the tube, and one thing I’ve noticed is that, on certain bus routes, it feels like I spend more time waiting at stops than actually travelling between them. And it doesn’t seem that it’s because they spend an excessive time at each stop - it seems to be due to bus stop proximity. It’s not uncommon that you can see one bus stop from the next. I understand this can benefit those with reduced mobility, but the tradeoff is, presumably, taking a bus significantly longer to traverse its route.