But unless you live near, and your destination is near, one of the widely-spaced bus stops, the additional walking time to and from the stop surely negates the quicker bus journey !
For very short journeys that could be the case, but for those other options such as walking or cycling (or mobility scooters or whatever) are likely to be more practical in any case.
For anything more than a couple of stops, an increase from 200m stop spacing to 400m stop spacing means you need to walk at worst an extra 200m (instead of ca 100m on each end, 200m at each end), around 2.5 minutes at 5km/h walking speed. That is conservative, since with sensible stop placement, it is likely that either the destination or the starting point will be closer than this. Average walking speed in London is also much higher than this.
Let's do a back-of-the-envelope calculation with the average bus journey in London:
To keep the maths simple, consider a journey of exactly 4000m, just under the average distance travelled on a london bus (2.7 miles according to Google), and assume all stops are exactly equally spaced.
London buses had an average speed of 9.3mph last year. Since that includes night time where buses are faster, we will assume this as their average travel speed between stops at peak times (this is an approximation, but probably a decent one).
At 200m spacing, and assuming 30s dwell times at each stop (fairly conservative), then the bus will need approx 48s between each stop. So to go 4200m on the bus (20 stops) it will need 20 x 48s and 19 dwells of 30s = 1530s or around 25.5 minutes. That assumes you get on just before it leaves and get off as soon as it arrives.
Now assume a spacing of 400m instead. Keeping everything else constant, that means you only need to go 10 stops instead of 20, so will need to wait 10 dwells of 30s, giving a total travel time of 20.5 mins and saving you 5 minutes on the bus.
But that doesn't take the time saving from braking and accelaration into account, as well as the effect of buses not getting in each others' way as much since they stop less. So lets assume, conservatively, that we can get the average travel speed of the bus up to 10.5mph. Then it takes us only 86s to go the 400m between stops on average. For our 4000m journey this gives us a moving time of 860s and a total journey time of 1160s or around 19 minutes. Adding on our worst-case 2.5 minutes extra walking time gives us 21.5 minutes.
So increasing the stop spacing in this way saves us 4 minutes on the average bus journey. For longer journeys the savings would be much larger, for shorter ones slightly less. If more segregation and bus priority were to be implemented, as well as all-door boarding, then then the average speed could probably be increased further and the dwell times reduced.
In reality, with congestion, intersections, uneven stop spacing and stops placed near high demand locations, the calculation becomes much more complex. The resultant time savings could potentially be much larger, or in some cases much smaller. But in general, increasing stop spacing will make most journeys faster overall, up to a certain point. For buses in urban areas, as the lowest rung on the public transport hierarchy, 400m seems to be widely accepted as the distance to aim for, whilst taking local demand patterns into account. This distance is easily walkable for the majority of the population. Since there are fewer stops you can also invest in making them more comfortable, by providing shelters and benches etc for older or less mobile people to rest, whereas with 200m spacing many stops are little more than a post with a bus stop flag on it.