No, that was not the only reason that occurred.

It certainly played a part to some extent, there is no denying that much. However, to argue that was the only (or even the main, which is a complex question too) reason would miss the many folks who supported it out of geopolitical or moral reasons.

The British provide a very good example of this. The British issued the Balfour Declaration, a statement of support for a "Jewish national homeland", because of an extensive and broad suite of opinions. Edwin Montagu for example, a Jew himself, opposed the Balfour Declaration at least in part because he feared it would cause backlash against Jews by painting them as dually loyal (a common trope Jews experience). Montagu claimed that this Declaration would make Israel his "national home" and thus lead to questions of his loyalty, back in 1917. Given the events of the next few decades, it seems hard to argue that it took this for Jews' loyalty to be questioned any more or less. Others, like Lord Curzon, stated that their problems were practical, concerned with how Jews could hope to make a state there at all.

How was this type of opposition overcome? Balfour himself believed that Jews given statehood would become equals of other peoples, and therefore treated better worldwide as their own recognized nation. This theory is relatively similar to what Herzl, one of Zionism's main proponents, pushed forward as well. Others, like Lloyd George (Prime Minister during the issuance of the Declaration) were influenced by "the desire to give the Jews their rightful place in the world; a great nation without a home is not right." Winston Churchill, who then was Minister of Munitions but not necessarily part of the Balfour negotiations, had gone on record in 1908 saying that a Jewish state would "be an immense advantage to the British Empire [and] a notable step toward a harmonious disposition of the world among its people", adopting both a geopolitical and moral reasoning. The most vigorous pro-Zionism members of the War Cabinet had experience fighting alongside Jews against the Turks in WWI (William Ormsby-Gore), fought for a Jewish unit to fight those Turks (Leopold S. Amery), and so on. Sir Mark Sykes is often described as a "convert" to Zionism, and was convinced (it seems from historical records) by Sephardi Chief Rabbi Moses Gaster, who "opened [his] eyes as to what this [Zionist] movement meant", by challenging his views of Jews as rootless, unprincipled cosmopolitans. Captain William Hall, another influence on Sykes, believed Jews had a strong moral and strategic case for material and political interest in a national homeland, and also felt it would counter Arab influence in the Near East, so to speak.

Did this sum up the support? No. As mentioned, antisemites also supported Zionism in some cases as well. This is not a unique dynamic by the way; white supremacists have sometimes supported Black nationalism in limited instances as a way to get de facto "segregation". In some cases, these motives intersected with Christian Zionism, which supported and supports a Jewish state because of the belief it will hasten the end of days, in millenarian fashion. Lord Balfour himself may have also been an adherent of this. But even moreso than this, the antisemitism that worked in favor of the Balfour Declaration also included theories of Jewish "power". Lord Balfour, for example, spoke of the "international power of the Jews", while Sykes spoke of how an endorsement of Zionism would help keep "Great Jewry" on the British side during WWI. Thus, the people who held very antisemitic tropes in their minds could hold those tropes alongside clearly stated beliefs of Jews deserving equality, self-determination, and being strategically helpful as well. How these interplayed is incredibly complex.

If you're curious for more about the British case around Balfour (the British would eventually become lukewarm to the idea later on), Schneer's The Balfour Declaration is good. For more about Sykes, you can read "Sir Mark Sykes: British diplomat and a convert to Zionism" by Cecil Bloom in Jewish Historical Studies. I think this dynamic is perhaps the most helpful in explaining the answer to your question, but I'm happy to expand on this if you have questions!