Basically, you cannot have radical societal or cultural changes because you have to get everyone on board ahead of time.
In a two party system and optional voting, you can have only a small fraction of the population who particularly want some changes actually get those changes. Also, this strategy can be used to destabilize a system away from local maximum (if we are searching for some better state).
A really good current example is same sex marriage. Australia is one of the last western countries to allow this (should be implemented before the end of the year), but it now has the support of 70% of the population. I would rather see change occur that lasts, than a small minority impose their will on the majority and having to deal with the resulting backlash.
Granted a lot of this is about stickiness of laws but it seems like a huge battle has to be fought for removing systemic inequalities, when that seems to be a major problem in the current system
It's only very recently that reproductive rights have broad majority support. The Civil Rights Act could never be enacted if it had required 70% support.
Once the battle is won then these rights get protected. At a time when systemic inequalities are at the forefront, inhibiting change seems like something that would go against the general political currents.
It is worth debating if the civil rights act should have been enacted before it had popular support. Rather than undermining the basis of suppression, imposing something on the majority without their support brings a resulting backlash that can last generations. We only have to look what drove the last 50 years of politics in the US south to see the result. From my comfortable perspective it might have been better to let the south come to its own opinion (with a lot of outside nudging) that things really had to change.
Its hard because laws that ensure basic civil rights go through the same process as tax law, but one is vitally more important for a better future for all
Yes relying on achieving popular support before acting will always mean that change happens later than it really should, but I think this price is worth paying to ensure long term support.
I do think political systems that reguire building broad popular support are desirable in general because they encourage openness.
You basically cannot get out of it unless you can convince most people that it's a good idea. With a 2-party system you can get someone who represents those people to rule for a while and maybe correct the course.
Also, with optional voting, we basically delegate decisions to those who really care about something. Having lived in a country with mandatory voting, I saw a few elections where people's views and the results of some elections were easily manipulated by false news close to the election day. People who are ambivalent I think are more likely to change their decision over such things.