Why do you think the odds in sports are generally better?

Actually, if we take top/default settings from well-known slot providers (e.g. 96% RTP), and compare it with a random soccer match today:

Atletico Madrid @ 1.50: 1 / 1.50 = 0.6667 (66.67%)
Draw @ 4.10: 1 / 4.10 = 0.2439 (24.39%)
Rayo Vallecano @ 7.00: 1 / 7.00 = 0.1429 (14.29%)

Total implied probability is 0.6667 + 0.2439 + 0.1429 = 1.0535

That gives us:
RTP is 1 / 1.0535 = 94.93%
House edge is 100% - 94.93% = 5.07%

So in this example, the sportsbook edge is 5.07%, which is actually worse than many slot games.