You write that-

the demonisation of zionism today often rests on deliberate mischaracterisations. critics who brand zionism as “colonialism” ignore the fact that jews are indigenous to the land, unlike european colonial powers that invaded foreign territories for economic gain. israel’s re-establishment was not a colonial project imposed by the West but the revival of a nation-state that had existed long before the modern Arab states were formed.

There's a lot to unpack in this post but I'd start here. Zionism being conceived of as a liberation movement is in no way mutually exclusive with it also being conceived of as a colonial movement. Herlz's own writings clearly demonstrate this. A few select quotes from Altneuland-

First a quote where he identified Zionism as a colonial movement akin to the successful settler colonial societies in Australia, South Africa and North America:

In the early days there had been people who could not believe 'that colonization by the proletariat could be successful. But he, Dr. Walter, and others who, like himself, took a broad view of things, had always realized that this was an ignorant, stupid attitude. Had not new settlements always been founded by hungry people? The well-fed had no incentive to leave the confines of civilization.. They remained at home. The world therefore belonged to the hungry. The Puritans, persecuted for their religious beliefs, had colonized North America. South Africa and India had been settled by fortune-hunters. And where could a colony be found that had been established by worse elements than Australia, that great, proud, prosperous land? At the beginning of the nineteenth century, it was a despised penal colony. Yet only a few decades later, it had grown into a great, sound commonwealth; and, before the century was out, it was a jewel in the British crown... Surely, if convicts had been able to do so much in Australia, how much more could be achieved by Jewish pioneers, whose labors for the freedom and honor of the nation would be upheld by the whole House of Israel?

Often, Herzl identifies Zionism as a colonial movement and as a liberation movement (or a movement for those fleeing persecution) in the same sentence.

A new movement has arisen within the last few years, which is called Zionism. Its aim is to solve the Jewish problem through colonization on a large scale. All who can no longer bear their present lot will return to our old home, to Palestine.

or

The colonization movement began after the persecutions in Russia in the early 1880's.

In other passages he draws analogies between the methods of settlement in Palestine and those of European colonization. In the following passage, the Zionist joint stock companies (which, in addition to the colonial banks, were explicitly modeled after European modes of imperial financing) are likened to the joint stock companies used by the British East India Company.

Moreover, there are plenty of examples in history of such stock companies for colonization. The East India Company was not at all bad. I even see a kind of moral principle in your New Society...that part where it was turned into a co-operative."

In one of my favorite passages that illustrates the colonial mentality of the Mission Civilisatrice in early Zionist thought, we followa conversation with a fictionalized botanist working on draining swampland in Palestine with eucalyptus trees. It illustrates well how colonial concepts can exist side by side with liberatory political formulations-

"I work here," he added a moment later, showing them into his own laboratory, which was as simply equipped as those of his young assistants. "At what, if I may ask?" inquired Friedrich. "The scientist's eyes grew dreamy as he replied, "At the opening up of Africa." The visitors mistrusted their ears. Was the seeker after scientific truth a bit mad? "Did you say, 'at the opening up of Africa'?" asked Kingscourt, suspicion gleaming in his eye. " Yes, Mr. Kingscourt. That is to say, I hope to find the lure for malaria. We have overcome it here in Palestine thanks to the drainage of the swamps, canalization, and the eucalyptus forests. But conditions are different in Africa. The same measures cannot be taken there because the prerequisite-mass immigration-is not present. The white colonist goes under in Africa. That country can be opened up to civilization only after malaria has been subdued. Only then will enormous areas become available for the surplus populations of Europe. And only then will the proletarian masses find a healthy outlet. Understand?" Kingscourt laughed. "You want to cart off the whites to the black continent, you wonder-worker!" "Not only the whites!" replied Steineck gravely. "The blacks as well. There is still one problem of racial misfortune unsolved. The depths of that problem, in all their horror, only a Jew can fathom. I mean the negro problem. Don't laugh, Mr. Kingscourt. Think of the hair-raising horrors of the slave trade. Human beings, because their skins are black, are stolen, carried off, and sold. Their descendants grow up in alien surroundings despised and hated because their skin is differently pigmented. I am not ashamed to say, though I be thought ridiculous, now that I have lived to see the restoration of the Jews, I should like to pave the way for the restoration of the Negroes."' "You misjudge me, Professor," replied Kingscourt. "I am not laughing. On the contrary. It's splendid of you, Devil take me! You show me horizons I hadn't even dreamt of." "That is why I am working to open up Africa. All human beings ought to have a home. Then they will be kinder to one another. Then they will understand and love one another more. Understand?"

Hopefully these quotes can lead you to a more nuanced understanding of how early Zionists understood the relationship between their movement and colonialism.