I think you vastly underestimate how many devs there are working for companies basically independently.
Ive been working as a developer for about 20 years now, and in IT for 30 - the first time I actually joined a “team” was less than a decade ago, before then I always worked as an individual developer for small companies (who usually had 2 or 3 devs, all working independently on stuff).
I would safely say that the number of devs who have no one checking their code, doing reviews, or engaging in standups is way higher than the number of devs doing those things.
What you describe is the ideal, something which has become pervasive in software dev circles as “the only way”, but it ignores that theres a huge body of devs out there that simply dont have that. Cant have a code review if the only other dev in your company works in a completely different language to you