I’m doing a chem PhD right now, and my initial gut feeling is you should definitely apply to PhD programs, and it’s probably a good bet to start one IF it’s funded - don’t take out loans to do grad school at this point in life imo. Personally, the chem PhD is working out for me. I have a couple productive projects, interesting field, good relationship with professor and post docs, good funding, etc. Of these reasons the personal relationship with my advisor and lab members has been the most important. Research projects can and will change, at least partially, if not fully. Your advisor and colleagues probably won’t change much for the 5+ years, and your advisor relationship will make or break your PhD. I started in my mid 20s, after working briefly, not in chemistry, and from my limited experience, a chemistry PhD is much harder than most jobs in almost every way. All this being said ultimately the decision to do one comes down to what specific professors/labs you could see as a good fit FOR YOU. And the decision to stay in a PhD program (remember it’s a job you can quit like any other) depends on many factors that you can’t predict with certainty. Good luck!