I'd be curious to know which 200 years you suppose they could have returned?
You may remember, when Muslims defeated the Eastern Roman Empire Byzantines, and took over Palestine, the reason was Byzantines became militarily exhausted by a long war with Persia.
Prior to that time, as far as I know, the Byzantines remained a powerful and vital force in the region.
I couldn't say how pro or anti-Jew Byzantines may have been. For certain, they would not allow an independent Jewish state in Palestine.
“I’d be curious to know which 200 years you suppose they could have returned?”
The time I am curious about is from 350/400-600AD.
The Romans were gone/diminished by then and Byzantium (my distinction from ‘Romans’) was not such an oppressive overseer that the Jews could not have reestablished.
Albeit, probably not fully independent but a presence non-the-less (akin to Judea under the Persians circa 450BC).
Whatever organization the Jews had before 75AD/135AD would have been still functional hence my Q as to why they were not motivated to reestablish in Judea at the soonest opportunity.
Byzantium did not engage the Muslims fully until after about 690AD (and that continued for 100+ years thru fall of Damascus, then from 3rd Crusade thru the final assault on Constantinople-1453AD) as the Mussies intentionally avoided the contact except in the closer Arabian peninsula/Persian area.
When Byzantium fell in 1453 it was from exhaustion of fighting Islam virtually alone with no help apart from some crusades. Persia had not before fallen to the Islamic Arabs.
But even the crusaders were of little help. The fourth crusade literally kneecapped Byzantium..never the same after that fiasco. Nothing like a Christian fighting another Christian to bring a smile on a Caliph’s face.
The Jews had little motivation to take back Jerusalem because the Khazars, a barbarian tribe in southern Russia, had just converted to Judaism, so a Jewish state existed already. You might also want to look up information on David Alroy, a 12th-century Khazar who tried leading a Jewish crusade from Iraq to the Holy Land, only to be assassinated when it got started.