So, checking Wikipedia, the trope has existed since the 1930’s, selecting the grandfather. Never the infant self, which should be the easiest to do, if suicide is the choice. So, clearly, it isn’t. Killing one’s infant self has lower impact on the timeline, so the paradox is less, even if its real and significant, so we don’t write the trope that way.
The Wikipedia page also conflates it with the “Killing infant Hitler” paradox. Again, you want a big effect. Not a “Stop Kristalnight” or “Block Wannsee Conference.” There doesn’t seem to be a neo-nazi authored “Block Potsdamn Conference.” These are things that would help, but that’s not what the trope is about, its about being so over the top, the timeline has to ripple and reset.
Many years ago, on the internet, probably the USENET, there was a discussion of time travel effects of second Terminator film. With the destruction of all Terminators, parts, raw data, the major scientist, and the last T-1000 in the molten steel, people argued the timeline had to (if successful, which it wasn’t because there were more films to make, but play along, please,) reset with a ripple, causing John Conner to disappear, leaving a very confused Sarah Connor with no memories of why she got herself so buffed, given that there was no reason or mechanism for John Conner to have been born.
The important thing is, however the paradox resolves itself, it can’t resolve itself in that way. Humans don’t just vanish. Their impact – food they ate in their lifetime, oxygen they breathed, CO2 they released, memories they formed, etc can’t simply ripple and replace. The explanation went that would be a violation of thermodynamics. Granted, this is intense physics happening, and you might say it supersedes thermodynamics. But really, if you don’t know thermodynamics, you don’t know anything. You can’t have no chance of knowing whats going on in reality, because then, its not reality. Even if its difficult to know reality, it has to at least be possible. Disappearing matter and energy just can’t be a thing.