Even ignoring all the structural issues like donors and media that prevent a truly open process the fact that Biden was the incumbent meant there was even more pressure from the DNC to not have a legitimate competitor run.

Saying she won the most delegates so she was everyone first choice is being basically blind to how the primary process actually operates.

If wealthy donors weren’t as important to the process, if she wasn’t the incumbent VP after a very unusual occupancy of the incumbent president stepping down this late, and you had something like ranked choice you would get a very different answer. This should be obvious to anyone because in the last “fair” primary in 2020 she and Biden were among the least popular candidates before the other centrists dropped out all together.