I'm a full time Ph.D. student. You might, of course, know that professors interact with the students very often (except if the professor is super busy always). I interact with mine almost every day. I do work with couple of collaborators in different countries. That is because my advisor knows them in-person before deciding to collaborate. I work with lab colleagues frequently. Remote makes all this extremely challenging.
"Disclaimer": I'm not in STEM
It's not a tactic I'd recommend to anyone unless their circumstances were strongly dictating it, and there's definitely stuff lost in the process. And my department wasn't particularly "collegial" - for the places that are, it'll be worse.
I would recommend against it in exceptionally strenuous terms for the PhD. Full-time on-site PhD or don't bother IMO. It just decreases the educational intensity and quality so much not to do that.
In academia however you can possibly build connections with your peers (other labs) and lab colleagues through your work. One can attend on-campus seminars and exchange ideas with potential collaborators. Being remote voids these options. Opportunities to work on interesting projects (other than research. For instance, contributing to student organizations) will be lost as well.
Edit: Regarding my research area. On most occasions, students will have to register for classes (not all classes are offered online). Once you complete classes, it is potentially viable to work remotely. However, it again depends on the funding scenario. How a student is supported etc. If I'm a Teaching Assistant, I'm expected to be on campus and available to students. Being a Research Assistant gives the flexibility to work remotely (if advisor agrees however not all universities might allow that).