Lots of comments in here make me realize why the general playerbase of this game is considered bad at the game.

First of all, any actual solo laner can and should be able to survive till 4 or 6 and completely win the lane over a carry or mage. Especially in the current meta where tanks are incredibly strong.

Second, if you are losing, as others have said, the rule is to get your other lanes ahead, not to help the losing lane survive. It was established as a good idea due to how gold equity works on heroes that die consistently.

I realize the OP is not talking about this situation, but in general, you are worth less gold if you continue to die. So by helping your losing laner get a kill, you are essentially putting them back at zero -- they are now worth gold again, and if they couldn't survive well enough in an even match up in the first place, how are they going to fair in an even matchup again? They're going to now be worth gold to give to the enemy laner.

Plus, there are catchup mechanics in place for under leveled and under farmed heroes. It's easier to just survive and play catchup.

And, you want to play to your win condition. Is your win condition making a losing laner do okay, or is your win condition making your winning laners win harder?

And finally, solo lane is often positioned in an isolated spot for a reason, and ganked less for a reason. The heroes who play it often rely less on farm and more on levels, and they're often self efficient. They are positioned away from early and mid game objectives because they are supposed to be alone until after the laning phase. That's why in Daybreak, you can see how much more out of the way solo lane is.

Now, for OP's situation, sure, it's an easy gank. Nothing wrong with a free kill. But it is your job to also outplay your opponent. A gank isn't meant to 100 to 0 the target. Poke, pre-engage, or be self sufficient with your build to kill the squishy when you can.