When people have less skin in the game, that does tend to skew behaviors.
Good thought @Hebegebe but how do you measure class rank? Texas defaults to the local school (which can work at the state level), but nationally? There is already a lot of blowback on any standardized testing and doubtful you could get a national benchmark on Top 10% (in fact, more schools are moving away from specific class rankings).
You first have to realize many states are in financial difficulties - just google state pension crises - and until you solve the pension and other post-employment benefits (OPEB) issues most states (and localities) have, more federal money will simply mean displacing (not supplementing) state dollars. Second, the free tuition ideas generally start with community colleges so yeah, those are both open admission and low graduation rates.
In fact, can you see a scenario where this idea is also not tied to outcomes (hey, we’re going to spend billions on free tuition but not also expect graduation rates to increase?).
If you look at other countries where college is “free”, you tend to see about the same (low to high 40%s) level of college graduates - because in those countries vocational/trade career tracks are pushed early and the admissions bar is set higher. Also, they don’t offer the same “co-curriculars” (ie sports, etc.) anywhere to the extent you see in the US (hence the per pupil is lower). Finally, those economies tax their citizens much more so in essence the “middle” class subsidizes much more than here those that go to college.