Medical schools are not “one size fits all” when it comes to admissions. Every medical school has a particular mission and a set of internal policies which guide their selection of students to interview.
Some schools value research highly; others don’t.
Some medical school highly value social activism and require (both formally or informally) a minimum number of community service hours. Others don’t.
Some medical schools have as their mission to train physicians for a particular region or to serve a particular ethnic or religious group. Others have a mission to train the future generation of medical researchers. Still others have a mission to develop the next generation of academic administrators, department chairs, and med school deans.
Yes, some medical school do consider what undergrad you attended, but it never a primary driver in admission decisions. Other factors hold much, much more weight.
Yes, you can start college at a community college and still become a physician. (Let’s just look at how many Surgeon Generals of the US have trod that exact path.) Is it ideal? No. Is is possible? Yes.
Can you attend Podunk Regional College as still go to medical school? Of course, but your journey may be more difficult than if you attend a better known school.
All medical schools considered the “road travelled” in acknowledgment that there are significant social and economic disparities in this country and not everyone comes from a background conducive to academic success. AAMC, through national policy statements, acknowledges that med school has become largely the purview of wealthy students and is attempting to provide a more opportunities to those from lesser economic circumstances.
I know personally about 30-40 young physicians. (My own children, their friends from high school through medical school and residency, the children of my neighbors and my friends, some of my former students.) I've heard their stories and know their accomplishments. I know several adcoms (both active and retired) personally. I have worked with physicians who sit on adcomms and who write the exam questions for specialty board exams. I have heard the same thing from ALL of them--students and adcomms alike. **There is no one path to medical school. **Every individual has to find the path that is best suited for that particular individual. (And, yes, that may or may not include research.)
BTW, my favorite story about undergrad research comes from a parent orientation session at a university known for its pre-med program. During the presentations, after a representative from the biological sciences dept spoke, a parent raised his hand to ask a question. His question, "What opportunities are there for my child to get involved in research as freshman?" The professor responded, "Tell him ask around. We always needs someone to feed the mice at 5 am."
Too often people who are not professional scientists don't understand there are many different levels of "research." Most of involvement in undergrad research does not require the application of critical thought & judgments. (That only comes after years of experience.) Much of undergrad research involvement is routine busywork. (aka "washing dishes")
During undergrad, students seldom get much past the "washing dishes" stage and become fully involved in the scientific process. Full involvement requires doing a literature review on a topic, developing a project idea, finding funding, refining the idea into a prove-able thesis, designing the test protocol, doing a test run of the protocol to see if actually tests what it purports to test, refining the protocol, doing another test run--rinse, repeat as needed. Science is a iterative process with many, many failures, false leads and dead ends. In fact, even in a successful project, there are many, many more failures than successes. Failure is a great teacher.