Bot is a lane that CAN snowball. If you gank bot, even if "all" you do is push the enemy away so they lose on gold and experience, and it can lead to your bot laner being ahead in gold and even a level, you've done good.
Repeatedly ganking bot also causes morale issues on the enemy team, so long your team doesn't go all "2 bot, gg" the moment you do it.
Repeatedly ganking bot is worth Elo. It's worth a lot of Elo. Do it, it's good.
Also, if you have top, and gank bot, lose top, but then get top, and keep doing it, but you always kill more of them than you lose (cause you retreat responsibly), and always manage to hold 4 points for 10-20 seconds at a time, and 3 points more or less at any given time, you're winning.
Does it matter if it's not the same 3 points non-stop but you keep trading, but are always ahead?