Nobody's talking about one issue, which is the quality of the students across the various higher ed institutions. It varies enormously.
Now don't get me wrong, please. I support all tiers of higher ed, and I think that CCs are vital. Some CC students end up there because they have no idea how brilliant they are -- or don't have a solid HS background, etc. I know this, for sure.
In a 4 year state college, which is the kind of place at which I spent my career, the students are better ON AVERAGE.
But folks, having spent some time with students at better state institutions (like flagship state universities) and elite institutions -- the students are significantly better there. Really, there's no comparison if you take the whole student population into consideration.
At my college I've had students who could have gone to any elite institution (but obviously didn't). Their minds and abilities were on a very high level. One or two of them, over the years, had come to us from a CC.
One of the things the OP needs to think about isn't just what field to enter, or where to go for that Ph.D., but the kind of institution he's likely to end up at, and he's going to have to look inside himself for that one.
Does he want to deal with remediation, with students who cannot write and cannot calculate and have very little general knowledge and among whom he will find gems, but mostly not? I have good friends who absolutely love that situation; it gives them enormous pleasure not just to find those gems, but to raise up poorly-prepared students who have some smarts and deserve a shot.
Same thing at the lesser 4 year state schools, but at a higher level. More gems, and the base knowledge level is going to be higher.
Then of course at the very good or elite schools, most every kid is smart and knows a lot. Different world!
All I can say for myself is that my own zeal to raise up my 4 year students flagged from time to time, but never went away. What I sometimes did tire of, though, was the constant battle to find words and images to teach my subject in ways that my students could understand.
I never, never thought of it as "dumbing down," but a hostile person might. I thought of it as a serious intellectual effort -- how can I best get this stuff into a format that works, so we can go from there, maybe. I regarded that as a skill. Most of my colleagues disliked teaching intro to our field, but I always loved it the most.
The few times I landed in an elite classroom (guest lectures, etc.) it was very different (not surprisingly). I found I didn't have to translate what I wanted to say ... I could just say it, and mostly be understood. I liked that.
My friends at VG/elite institutions bust their butts all the time. There's enormous pressure on them and they do very little besides be college professors. It occupies their whole lives.
At a lesser place it doesn't have to be like that. At my place I had considerable freedom to do other things besides be a professor (after I jumped through all the initial hoops, got the book out, etc.). This was important to me, which is why I stayed.
So I think one thing for the OP to think about how much he's interested in "the life of the mind," and how much he's willing to sacrifice for that.