I can only give you my N=1 experience (approaching 6 months into my residency).
What is the benefit of doing residency?
1) Competition for hospital placement.
Many locations (think metro and/or nearby cities and counties) screen out applicants who do not have a PGY-1. Why? Its due to the ratio of applicants to job availability. Unless you are an expert of networking beforehand in certain regions with certain people, it is awfully difficult to simply apply for a hospital job when you have multiple applicants that have already gone through the rigors of residency. What do you bring to the table as a new pharmacy graduate vs licensed pharmacist with a PGY-1?
Why should A student consider it?
My above comment plus this:
1) Variety of experiences in different departments in a concentrated format.
Residency focuses on getting exposure to different departments of the hospital
while working under your own license (critical care, internal medicine, ID). This expedites you to be "well rounded" in all settings in a short matter of time vs training a new graduate.
2) Specializing requires a PGY-2 (ID, Oncology, Informatics) and you can no longer skip a PGY-1 to go straight into a PGY-2 per ASHP.
If you wish to specialize and forgo a PGY-1, you won't be able to push forward with a PGY-2 in your specialty of choice. Outliers exist, but you'd be hard-pressed to climb that mountain without a PGY-1.
What do you learn and do during residency year that preceptors don’t teach you during APPEs?
1) Multi-tasking under your own license.
You still get assigned a preceptor to have your discussions (patient workups and case studies) but before long, you're on your own going to daily rounds, making medication adjustments, and following up DI questions in a fast-"er" pace environment
without someone looking over your shoulder. This is part of the shaping and molding process. Again, with the variety of experiences in a short amount of time with a PGY-1, you should be able to walk into a hospital and be fundamentally & adequately prepared. Sure, you could do it straight out of graduation (so long as you're teachable), but your pace will be nowhere to that of a PGY-1 grad and (again) with plenty of applicants, the hospital would find it difficult to justify picking you over someone else for the position.
How Much of a difference does 1 year of residency make vs a full time pharmacy job?
3 years of experience is equated to 1 year of residency.
That is the ratio (YMMV)
So, if you want to work hospital with no desire to specialize and believe you can do it without a PGY-1 (or work retail/community), I say avoid residency altogether. Otherwise, you'll have to run the gauntlet and
embrace the suck while working & rapidly building up your clinical skills.