There's a big difference between microbial life and intelligent life.
Bostrom and others have argued that, based on how long evolutionary milestones took on Earth, the "difficult step" is actually complex multicellular life.
Bostrom and others have argued that, based on how long evolutionary milestones took on Earth, the "difficult step" is actually complex multicellular life.
https://www.nature.com/articles/s41598-019-39558-8
https://www.sciencemag.org/news/2018/06/momentous-transition...
I agree with your conclusion that Fermi's paradox simply means there is no other intelligent life, though I think the jury's still out as to where the filter is.