A Tesla Model 3 weighs 3,582 lbs. Even if you chose a Smart Fortwo (1,984lb) as your comparison instead of an equivalent-size ICE vehicle, it's still not doubling the weight.

I'm not really. The vast majority of infrastructure degradation is because of trucks which weigh 100 times as much as cars. Their weight will be decreasing by a much smaller factor.

No, because it's still going to be negligible compared to the wear done by trucks. The average 18-wheeler weighs ~80-90,000 lbs, and the relationship between wear and weight is exponential, not linear. So while 25 Teslas weigh the same as a single 18 wheeler, the 18 wheeler contributes a lot more to road wear than those 25 Teslas. And in any case, infrastructure costs are going to be a rounding error to the economic costs associated with climate change.

My e-bike weighs a lot less then the car it replaced.

Heck, even the safety aspect. And the mining of materials. The recycling aspect (or lack there of), or the disposability of the vehicles if the battery/charging system bricks itself. The Chevy Volt forums are full of people losing thousands of dollars because their low miles car worth about $10k, needs a $10k battery module or two.