I know that it suck2 not to have the college experience you expected, and class of 2024 really has had it rough.
However, the difference between colleges that enacted strict COVID 19 restrictions and those that didn’t is the 0.1% positivity rate that you mentioned. The Delta variant hit many younger people than the previous variant, and there are far more breakthrough cases.
There are colleges like Rice that have moved online because of surging cases of COVID 19, mostly because the college did not have as restrictive policies as Brown does.
Ask yourself - would you rather have:
A. Brown-level restriction, on campus, in person
B. Lower restrictions, and then move to online for the rest of the semester
C. Dozens to hundreds of cases per week.
D. Small, rural campus.
That is exactly what they are trying to do. Moreover, you should also consider the fact that faculty, staff, and older graduate students are also part of the Brown community.
You may consider yourself as being safe from COVID 19, since you are a healthy, young, and hopefully vaccinated person. However, almost all of your faculty members are over 30, most are over 40, and many are older than 50 or 60.
The staff is also older than students, and they are even more exposed to infection than faculty.
So on one hand you have “the student undergraduate experience”, and on the other hand, you have the health and lives of staff, faculty, and the students themselves. So if only the students were at risk, then perhaps the risk of infection, complications, and death from COVID may not be worth the possible effects of stress, maybe. But when you start adding the risk to Faculty and staff, not to mention the surrounding community, then the risk from COVID 19 far outweighs the fact that students are not having the “college experience” for which they hoped.
If sucks, yes, but not as much as it would suck if faculty and staff were getting sick, suffering from long term complications of COVID, and dying.
PS. While you may be assuming that teaching you and your fellow students is the primary function of faculty, in fact, that is only about 40% or less of their job. They also do research, advise graduate students, and perform assorted administrative duties. So risking themselves for part of their duties makes even less sense.