That is not unexpected. There are three forms worth considering, actually: bacteria, archaea, and eukaryotes. The first two share DNA/RNA replication, but they operate in completely different ways. The third is dramatically more complex than either of the former two, yet emerged from them. Once the first two existed, they rapidly filled almost all possible niches available at that time, and there was no space for a third form to emerge (lest it be immediately consumed by the first two), unless that third form was exceptionally competitive (like eukaryotes were and are). The first two forms did emerge relatively early on. The third form, representing one of the most stunning advances in the history of life on Earth, took over two billion years of 10^35+ ops/second of continuous computation to emerge. In terms of total compute, that's about 10^25 greater than today's largest known frontier training run. After that point, evolutionary selection pressure began operating at higher levels of abstraction, selecting for complex multicellular morphological form and later on intelligence, culture, and beyond, over several additional billion years, while bactera and archaea continued to consume all available microscopic niches.
Beyond that, life itself modified the environment that produced the original process of abiogenesis. The early Earth featured a carbon-rich acidic ocean. After life emerged, metabolism began altering the planet’s redox chemistry, consuming available chemical free energy, transforming atmospheric and ocean composition, and eventually oxygenating the surface environment. In other words, the machinery that produced life was not left running in the same state. This is why I called it a self-modifying search engine -- search accelerants operate by changing the search landscape that the engine operates over.