Scotland is quite big, the roads are variable, so even today it takes some effort to travel between some of the more remote hills. When we today think of a long walk in from the road to something like Seana Bhràigh which has a 8 mile walk in we think of it was remote. How long must the walk in's in Munro's day been? Less roads, no cars, all travel by train, horse, bike or foot. The West Highland railway was opened in 1894, so the train would have been some some use in some areas. No Gore-tex, no light weight ice gear, GPS or even accurate maps. I expect he had more than 24 days holiday a year to explore, so did not have to try to get as many done in a day as he could.
I have done about 90 of the peaks over the last 20 years. I do a few a year and the vague goal of doing them all before I get put in my box is an excuse to explore and experience wild Scotland. How much better Munro must have got to know Scotland, not just the mountains, but the bits between.