Montreal Gare Centrale's 28 departures/day doesn't even make the top 30 let alone the top 3.
1. Toronto Union (too many to count)
2. South Keys:
89 Line 2 northbound
89 Line 2 southbound
89 Line 4
TOTAL = 267 departures/day
3-4. Weston, Bloor:
79 UP Express westbound
79 UP Express eastbound
30 Kitchener Line westbound
30 Kitchener Line eastbound
TOTAL = 218 departures/day
5-12. Corso Italia, Dow's Lake, Carleton, Mooney's Bay, Walkley, Greenboro, Leitrim, Bowesville
89 Line 2 northbound
89 Line 2 southbound
TOTAL= 178 departures/day
13. Uplands
Same as Line 2 stations
14. Guildwood:
41 Lakeshore East westbound
41 Lakeshore East eastbound
10 Via Ottawa eastbound
8 Via Ottawa westbound
5 Via Montreal westbound
5 Via Montreal eastbound
TOTAL = 110 departures/day
15. Oakville:
50 Lakeshore West eastbound
43 Lakeshore West westbound
4 Via Windsor westbound
1 Via Maple Leaf southbound
5 Via eastbound
TOTAL = 103 departures/day
16. Clarkson:
48 Lakeshore West eastbound
48 Lakeshore West westbound
TOTAL= 96 departures/day
17-19. Bayview, Limebank, Ottawa Airport
TOTAL = 89 departures/day
20. Burlington
45 Lakeshore East eastbound
43 Lakeshore East westbound
TOTAL = 88 departures/day
21-22. Appleby, Bronte
43 Lakeshore West eastbound
41 Lakeshore West westbound
TOTAL = 84 departures/day
23-29. Danforth, Scarborough, Eglinton, Rouge Hill, Pickering, Ajax, Whitby
41 Lakeshore East eastbound
41 Lakeshore East westbound
TOTAL = 82 departures/day
30.Aldershot
45 Lakeshore East westbound
26 Lakeshore West westbound
5 Via Windsor westbound
1 Via Maple Leaf southbound
5 Via eastbound
TOTAL = 82 departures/day
31. Pearson Terminal 1
TOTAL = 79 departures/day
etc.
If you want to compare Line 2 to other mainline rail services, you should also compare average speeds to provide the necessary context. In which case Line 2 scores extremely poorly. UP Express takes 11 fewer minutes to cover 3 more kilometres than the Line 2 for example: