"Right to exist" is a misnomer.

Israel exists, and anti-Zionism is wanting it to not exist.

Palestine does not exist.

What exists is two geopolitical entities, West Bank and Gaza, which are:

- geographically separate, not even sharing a border

- historically coming from being occupied by different countries (Jordan and Egypt)

- ruled by different entities (PLO and Hamas, respectively)

- ...with different ideologies (PLO/Fatah is a secular terrorist group, Hamas/PIJ are fundamentalist Islamist terrorist groups)

- ...and have been at war with each other for the past 20 years - and are at war to this day[1] in spite of attempts[2] of other countries to mediate the conflict.

Sure, Yugoslavia also existed even though Yugoslavs weren't a thing.

It also didn't end too well, if you remember the 1990s[3].

[1] https://en.wikipedia.org/wiki/Fatah%E2%80%93Hamas_conflict

[2] https://www.newarab.com/analysis/moscow-mediator-why-russia-...

[3] https://1997-2001.state.gov/regions/eur/fs_990331_ksvo_ethni...

Nothing about Zionism says so. People supporting a two-state solution are Zionists.

Also, side question: would you be happy if we returned to the pre-1967 borders of Israel and Palestine?

It was the Ottoman Empire, then British, then Israel.