We're not even talking direct democracy, here. The parent post is saying (for example) that a single Senator can prevent a bill from entering the Senate, even if said bill would get a majority of Senate votes.
If it was possible to get such bills put to a vote over the objections of singular individual representatives, then there would be less need for direct democracy.
Switzerland is not a direct democracy. No country is. Some have more democratic processes, at the extreme ends being Switzerland, Finland, and I suppose Germany, while at the other end, with least democratic processes being US among others. US has great constitution/rights, terrible democratic system.
I suppose you're looking for this type of system [0]. Switzerland is a proud and well-known defender of it.
[0] https://en.wikipedia.org/wiki/Direct_democracy