We all know that having a single turn (like in the US) leads to a political landscape with 2 major political parties and few nuances (but the major problem in the US system is "the winner takes it all" policy in most states: if the number of members of the electoral college were proportional to votes in each states, the results would already be more fair)
But the French system (with 2 turns) is also very far from optimal and non-linear, and also leads (to a lesser extent, and some variants/surprises) to 2 major political parties + some smaller "satellite" political parties. And some issue are for example that
* sometimes, a candidate that would win against all others has a too low score at the first turn to pass to the 2nd turn (this is what happens in 2007 where all polls said that François Bayrou (who was center/moderate and more consensual) would have won both against Nicolas Sarkozy and against Ségolène Royal, but couldn't get enough votes to pass the 1st turn)
* sometimes, the opposite issue happens i.e. a candidate that has no chances to win the 2nd turn has enough votes to pass the 1st turn: this is what happened in 2002 when Le Pen (extreme right wing) supplanted Jospin and went to the 2nd turn (that Chirac was then 100% certain to win at that time, with a consequence that there were no real/constructive debate about the programs)
* some people who have new ideas cannot participate because you need 500 signatures of already-elected people in order to participate (so if you are not a member of an established political party, it's very hard to become a candidate to the presidential election)
Just to say that there is no binary split between "democracy" and "dictature" : the voting system and algorithm influences a lot the political landscape and therefore the debates. Maybe people here are familiar with the Condorcet method used (among other things) in https://www.debian.org/vote which is better in my opinion (yet a little bit difficult to implement in a wider scale such as a presidential election). Another approach / voting method that I quite like is this one (only in French, sorry) https://fr.wikipedia.org/wiki/Jugement_majoritaire : I like it because 1°/ it is simple to implement and to understand, 2°/ it would inherently avoid the issues above and forces the candidates to be more consensual (i.e. to become "president for everyone") rather than cleaving, while still enabling nuances to express during the debates (not only on a "binary" axis left/right).