Weight is definitely a factor in drive life. A friend of mine built a 900hp motor and put it in a 23' cat with a Bravo1. He told me it's been running for three years without failure.
My boat is 24' and weighs 2400lbs dry, up to 3200lbs with 110gal fuel. It has a 600hp motor and the old style Bravo1. I do NOT do any holeshots. So far so good, but I wish I had a stronger drive.
My boat/trailer weighs 5000lbs and I pull it with a 1 ton Dodge diesel pickup. I believe in overbuilding for strength. That way machinery lives longer.