Well I'm not a perfect example of shying away from the tier's most powerful pokemon as I use Milotic, so I'm unfit to judge, but Venusaur is one of my favorite pokemon and I personally dislike seeing his saturation is usage. You are one of the very few people recently to use him well. Faking a Scarf, Leech Seeding to scout, and using a super powerful LO Leaf Storm to catch the switch in or KO Rotom.
Venusaur's "counters" can by and large beat one set and lose to another, Leaf Storm+Sludge Bomb being the hardest to deal with from what I've seen.
I couldn't risk switcing Houndoom into an attack, and knew that in early game even though I got him in he was limited to scouting his counter(s).
I switched in Steelix on a predicted T-Wave, by the way.