So what you're saying in the OP is basically correct--there never was an autonomous government in the region that called itself "Palestine" (until today, basically). The term was mostly geographical in ancient times, and was used as the name of governmental administrations from 135CE all the way through the Ottomans, more or less. So while there wasn't a Palestinian country, there people called the area Palestine and the governmental subdivision in the area was sometimes called Palestine (the names of Ottoman provinces are confusing and changed a lot, so exactly when is beyond me, but it was often a name for the region in government). And while today the term can be politically loaded, that's a relatively recent innovation.

Also, the bit about never fighting in any wars isn't quite correct--in 1947 and 1948 there were Palestinian Arab militias which fought against Jewish militias in the earlier stages of the war, but these were mostly disarmed by Jordan when the war had more intervention from Arab states.

This is occasionally an important distinction, because vague use of the name "Palestine" can give people misleading ideas about the political history of the region, like this one I wrote about here.

Because there never was a palestinian state? There is a difference between nationality/ ethnicity of people and a state. The palestinians never had a state.

The land was most of the time under the rule of various empires. The last one was the British Empire. This isn't debatable.

But what I think is more interesting is, when Palestinians actually start to be Palestinians, instead of muslim Arabs. This is a pretty debated topic without a clear answer. It, at earliest, started in the 19th century together with other national identities in the declining Ottoman Empire. Others argue that it started in response to jewish immigration to the land. Because the immigrating jewish population specially didn't identify as Palestinian, but as Zionist Israelis (even before the creation of the Israeli state). The case with the Jewish population that "always" lived there is more complicated.

The actual question who is Palestinian, what makes them Palestinian and who isn't Palestinian but lives there is a question up to debate without an easy or clear answer.

edit: What I mean with the last sentence: National identity alone is complicated, but in the region it gets infused with religious ideas which makes it even more complicated. Are Betlehem Christians Palestinians? Are Druze Palestinians? If you ask the Betlehem Christians they probably self-identify (or identified) themselves as Palestinians. Hamas would probably say they aren't. Druze may share common background with Muslim Palestinians, but most of them have Israeli citizenship. Are muslim Arabs living in Israel with israeli citizenship Palestinian or Israeli?