imo big problem with top snowball is tower plates punishing roams
generally speaking all the super good roamers who can run to a lane and get back quickly are mid laners, and also they get better access to bottom lane so the reward risk is less skewed.
In top lane where the champion pick matters a lot more because you're up to 1v1 more it can sometimes set you back just as much as dying would if you try to roam, especially if you didn't pick up the kill. You're kind of on a timer to get that gold while the other guy has 14 minutes to knock you silly and can freepush for tower money if you leave.
I don't think people talk about this enough because I definitely feel like I exploit it hard in favorable matchups and when a lot of champs have counterplay heavily revolving in beating them on the map not in lane, this setup ends up inflating their value a lot.