Where is this happening? I have read the opposite that STIs are at super high rates.
Condoms work at preventing HIV infection, transmission, etc. and against infection/transmission of other STDs. I am technically a top/giver and I have no issues using confoms for anal or vaginal sex.
Also, not everyone that claims to be on prep or the Truvada really is, they do not all get tested for HIV or other STDs, and I know men who order it online, and who are on it but do not take it daily.
I have a friend that has been poz since the early 1980s and he thinks neg guys taking prep instead of using condoms is a disaster waiting to happen. He has taken all of the meds from the start with AZT if you remember this or were around for it, and said they all have bad side effects both short and long term. My friend does not date or sleep with men on prep or who say they are "neg" and on prep as they just want unsafe sex, he only dates other poz men, and condoms are used as unsafe sex between two or more poz people results in their meds not working as well, there are other strains of HIV and reinfection with the original strain or new variant/strain can happen.