nearly every toplane matchup can snowball either way, so giving some early ganks to swing the lane in your favor usually means you can focus on bot/drag post lvl 6 when it matters and not worry much about top anymore, so camping top early is always a thing if you know when to switch your attention to drag.
toplane is home to all and everything, melee carrys, tanks, bruisers, mages, supports, adc.. and it's mostly the length of the sololane that causes the snowball.
in mid you have less distance so less lanefreezing and zoneing and a easier rute to savety, and bot you have two guys that can protect each other a bit.
hardcounters on a snowbally lane are a issue. As soon as you forced to blindpick, your ad a huge disadvantage, and one team has to blindpick top.