The tide comes in and gently brings more material for life to form and gently meandering rivers add to the serenity. What a beautiful picture. Now let's take a quick glimpse of reality. The tidal lagoon idea NEEDS everything to be calm and gentle or else it will disrupt the material and carry it back to sea. What proclaimers of this hypothesis fail to recognize is what the early earth really would have been like. According to secular scientists, the moon was much closer to the earth than it is today. It caused the tides not to be gentle waves but raging tsunamis hundreds and even thousands of feet high that swept over the continents 2-3 times per day. Nothing like being pummeled by billions of gallons of water to break the serenity, huh? Already the chances of abiogenesis are being ruined and we've hardly begun! I dunno if tidal lagoons really are proposed as a serious hypothesis, but this argument against them backfires badly. A 1000 foot tall tide would create tidal lagoons for miles & miles inland. It would create many more tidal lagoons than we'd ever think of seeing today!
That would depend upon the land topography. It is still just one point – and there are far more important ones…