Right.

One of the things I won't miss about my last apartment (which was overall pretty fantastic) was how the plumbing was under-built when they constructed the otherwise overbuilt building back in the 60s or 70s.

This meant that on my end of the building, all 4 apartments (mine, the other one on my level at the end of the hall, and the two above us) all shared the same undersized drainage piping.

I was there 6 years, and averaged about 1.5 horrific backups per year that required a call to management, who had to come out, try to fix, then give up and call professionals (and twice in that 6 year span, the professionals even gave up and had to call in even more capable professionals).

In every case, I always asked them if there was anything I could be personally doing...or not doing...that might help.

In each case, the plumbers always said I was doing everything I could, even above and beyond considering the more capable drain filters I used on both sink and tub, and that the real issues were the long hair from the ladies in all 3 other apartments (not a criticism on them, just an observation that many of the clogs were long hair, vs my buzz cut), and in a few of the worst cases, flushed hygiene products (which prompted a mass email from the landlord that these things were not to be flushed, both feminine hygiene stuff and "flushable wipes")...and in the worst backup, the two young girls in the family above me had flushed a wash cloth.

That last one was the worst by far. Had disgusting, chunky shit water/gray water cocktail backing up into toilet AND shower.