Yes, and these oceans formed 4.5 billion years ago, aka. much longer than "few tens or hundreds of million years" > then consider that the medium between the s

Yes, and these oceans formed 4.5 billion years ago, aka. much longer than "few tens or hundreds of million years" > then consider that the medium between the source and destination is a frozen vacuum which means you have billions of years for transmission and spreading. And by what means does that spreading take place? Spreading implies a medium through which to spread, which doesn't exist in interstellar space. So that leaves moving over that distance on a fragment of a shattered planetoid for example. The fastest known asteroid, 2021-PH27 clocks at around 106 km/sec. Meaning, it would require about 2800y to make it's journey (remember, this is still alpha centauri I'm talking about, which by all accounts has no planets in the habitable zone). 2800 years at top speed thorugh the vacuum of space, unshielded from the denaturing effects of cosmic radiation. And at the end of that travel, if it isn't swallowed up by the gravitational forces of the sun or our 2 gas giants, an impact event comparable to a large thermonuclear device going off. Sorry, but compared to that, sponeneous abiogenesis sounds a lot more plausible to me.